Arcane Sanctum enters the battlefield tapped.

{T}: Add {W}, {U}, or {B}.

Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, tap up to X target creatures, where X is the number of times this creature has mutated. Those creatures don't untap during their controller's next untap step.

Mutate {5}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times this creature has mutated. Put those permanent cards onto the battlefield.

Bad River enters the battlefield tapped.

{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Whenever you cast a creature spell, draw a card.

Deathtouch

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

{1}{G}: Regenerate Blight Mamba.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Blighted Agent can't be blocked.

Trample

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Whenever Bloated Contaminator deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mutate {2}{B/G}{B/G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, return target permanent card from your graveyard to your hand.

Mutate {2}{U/B}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

You may cast Brokkos, Apex of Forever from your graveyard using its mutate ability.

({T}: Add {G} or {W}.)

Canopy Vista enters the battlefield tapped unless you control two or more basic lands.

Indestructible

{T}: Add {C}.

{5}, {T}: Add five mana in any combination of colors.

Mutate {3}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Menace (This creature can't be blocked except by two or more creatures.)

Whenever this creature mutates, each opponent discards a card.

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, each opponent sacrifices a creature.

({T}: Add {R} or {G}.)

Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

Mutate {3}{R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Reach

Whenever this creature mutates, you may discard a card. If you do, draw a card.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

{T}: Add one mana of any color in your commander's color identity.

Crumbling Necropolis enters the battlefield tapped.

{T}: Add {U}, {B}, or {R}.

{T}: Add {C}.

{5}, {T}: Add {W}{U}{B}{R}{G}.

Mutate {2}{W}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Lifelink

Whenever this creature mutates, create two 1/1 white Cat creature tokens with lifelink.

Mutate {4}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Flying

Whenever this creature mutates, destroy target creature or planeswalker an opponent controls.

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, draw a card.

Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum.

Mutate {3}{R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, create a red artifact token named Feather with "{1}, Sacrifice Feather: Return target Phoenix card from your graveyard to the battlefield tapped."

Landfall -- Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

{T}: Add one mana of any color that a land an opponent controls could produce.

{3}{G}{W}: Monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)

As long as Fleecemane Lion is monstrous, it has hexproof and indestructible.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Flood Plain enters the battlefield tapped.

{T}, Sacrifice Flood Plain: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Frontier Bivouac enters the battlefield tapped.

{T}: Add {G}, {U}, or {R}.

Deathtouch

Whenever a creature you control with deathtouch deals combat damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Mutate {1}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Reach, trample

Whenever this creature mutates, destroy target artifact or enchantment an opponent controls.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Reach

Whenever this creature mutates, put two +1/+1 counters on it.

Grasslands enters the battlefield tapped.

{T}, Sacrifice Grasslands: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Mutate {2}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, other creatures you control get +X/+X until end of turn, where X is the number of times this creature has mutated.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Mutate {3}{R/G}{U}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying, trample

Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.

Mutate {2}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Deathtouch

Whenever this creature mutates, each opponent loses X life and you gain X life, where X is the number of times this creature has mutated.

({T}: Add {U}.)

({T}: Add {U}.)

Double strike

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Companion -- No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)

{T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs.

Jungle Shrine enters the battlefield tapped.

{T}: Add {R}, {G}, or {W}.

Krosan Verge enters the battlefield tapped.

{T}: Add {C}.

{2}, {T}, Sacrifice Krosan Verge: Search your library for a Forest card and a Plains card, put them onto the battlefield tapped, then shuffle.

Mutate {U/R}{U/R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, return target instant or sorcery card from your graveyard to your hand.

Mutate {3}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Vigilance

Whenever this creature mutates, you gain 4 life.

Mutate {2}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, exile the top card of each opponent's library face down. You may look at and play those cards for as long as they remain exiled.

Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, exile the top card of each opponent's library face down. You may look at and play those cards for as long as they remain exiled.

({T}: Add {R}.)

({T}: Add {R}.)

Mountain Valley enters the battlefield tapped.

{T}, Sacrifice Mountain Valley: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

({T}: Add {G}.)

As Murmuring Bosk enters the battlefield, you may reveal a Treefolk card from your hand. If you don't, Murmuring Bosk enters the battlefield tapped.

{T}: Add {W} or {B}. Murmuring Bosk deals 1 damage to you.

Mystic Monastery enters the battlefield tapped.

{T}: Add {U}, {R}, or {W}.

If {U}{B} was spent to cast this spell, search your library for a card, put that card into your graveyard, then shuffle.

Return up to two permanent cards from your graveyard to your hand.

Mutate {2}{W/B}{W/B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

When Necropede dies, you may put a -1/-1 counter on target creature.

Mutate {4}{G/W}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Deathtouch, lifelink

Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield.

Nomad Outpost enters the battlefield tapped.

{T}: Add {R}, {W}, or {B}.

Opulent Palace enters the battlefield tapped.

{T}: Add {B}, {G}, or {U}.

Mutate {1}{B}{G}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature deals combat damage to a player, return target creature card with mutate from your graveyard to your hand.

Converge -- You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Mutate {G}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

{1}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield. If you don't put the card onto the battlefield, put it into your hand.

Flying

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

At the beginning of your upkeep, you draw a card and you lose 1 life.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

{T}: Add {C}.

Flying

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

({T}: Add {W}.)

({T}: Add {W}.)

Each creature spell you cast costs {1} less to cast if it has mutate.

Whenever you cast a creature spell, if it has mutate, draw a card, then discard a card.

Mutate {2}{R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

{T}: This creature deals X damage to any target, where X is the number of times this creature has mutated.

Mutate {3}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Whenever this creature mutates, you may return target creature an opponent controls to its owner's hand.

({T}: Add {W} or {U}.)

Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

First strike

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Mutate {1}{R/W}{R/W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, other creatures you control get +2/+1 until end of turn.

Rocky Tar Pit enters the battlefield tapped.

{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Whenever a creature dealt damage by Rot Wolf this turn dies, you may draw a card.

Sandsteppe Citadel enters the battlefield tapped.

{T}: Add {W}, {B}, or {G}.

Savage Lands enters the battlefield tapped.

{T}: Add {B}, {R}, or {G}.

Mutate {3}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature mutates, destroy target noncreature permanent. Its controller creates a 3/3 green Beast creature token.

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flash

Whenever this creature deals combat damage to a player, draw a card.

Seaside Citadel enters the battlefield tapped.

{T}: Add {G}, {W}, or {U}.

Toxic 2 (Players dealt combat damage by this creature also get two poison counters.)

Whenever another creature you control with toxic attacks, it gets +1/+1 until end of turn.

({T}: Add {B} or {R}.)

Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Mutate {2}{B/R}{W}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Double strike

Whenever this creature mutates, it deals 4 damage to target creature or planeswalker an opponent controls and you gain 4 life.

Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, gain control of target noncreature artifact.

({T}: Add {U} or {B}.)

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Mutate {3}{G/U}{G/U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Whenever this creature mutates, create a 3/3 green Beast creature token.

Mutate {1}{W/U}{R}{R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying, first strike

Whenever this creature mutates, you may cast target noncreature card with mana value 3 or less from your graveyard without paying its mana cost.

Lifelink, toxic 1

Whenever you proliferate, choose one --

• If you don't control a creature named The Hollow Sentinel, create The Hollow Sentinel, a legendary 3/3 colorless Phyrexian Golem artifact creature token.

• Target artifact creature you control gains flying and lifelink until end of turn.

Flying

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

When you proliferate, return Voidwing Hybrid from your graveyard to your hand.

Mutate {2}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying

Whenever this creature mutates, put a +1/+1 counter on it.