{T}: Add one mana of any color in your commander's color identity.
{5}{G}{G}{G}
Craterhoof Behemoth
Creature - Beast
Haste
When Craterhoof Behemoth enters the battlefield, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.
5 /
5
{3}{B}
Deadly Rollick
Instant
If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.
{1}{B}
Demonic Tutor
Sorcery
Search your library for a card, put that card into your hand, then shuffle.
{4}{G}
Doubling Season
Enchantment
If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.
--
Gaea's Cradle
Legendary Land
{T}: Add {G} for each creature you control.
{1}{R}
Impact Tremors
Enchantment
Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.
{3}{G}
Parallel Lives
Enchantment
If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
{3}{R}
Purphoros, God of the Forge
Legendary Enchantment Creature - God
Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.
6 /
5
{B}{R}{G}
Slimefoot and Squee
Legendary Creature - Fungus Goblin
Whenever Slimefoot and Squee enters the battlefield or attacks, create a 1/1 green Saproling creature token.
{1}{B}{R}{G}, Sacrifice a Saproling: Return Slimefoot and Squee and up to one other target creature card from your graveyard to the battlefield. Activate only as a sorcery.
3 /
3
{1}{G}
Sylvan Library
Enchantment
At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.
--
Urborg, Tomb of Yawgmoth
Legendary Land
Each land is a Swamp in addition to its other land types.
--
Yavimaya, Cradle of Growth
Legendary Land
Each land is a Forest in addition to its other land types.