Commander creatures you own have "The first Dragon spell you cast each turn costs {2} less to cast."

As Belbe's Portal enters the battlefield, choose a creature type.

{3}, {T}: You may put a creature card of the chosen type from your hand onto the battlefield.

Whenever a creature enters the battlefield under your control, you may look at the top X cards of your library, where X is that creature's power. If you do, put one of those cards on top of your library and the rest on the bottom of your library in any order.

Flying

Whenever Ganax, Astral Hunter or another Dragon enters the battlefield under your control, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Choose a Background (You can have a Background as a second commander.)

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.

Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)

Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

When Grave Sifter enters the battlefield, each player chooses a creature type and returns any number of cards of that type from their graveyard to their hand.

As Icon of Ancestry enters the battlefield, choose a creature type.

Creatures you control of the chosen type get +1/+1.

{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Whenever a creature with power 4 or greater enters the battlefield, its controller draws a card.

Enchant creature

When Kenrith's Transformation enters the battlefield, draw a card.

Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

As long as you control three or more legendary creatures, Kolvori gets +4/+2 and has vigilance.

{1}{G}, {T}: Look at the top six cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

As The Ringhart Crest enters the battlefield, choose a creature type.

{T}: Add {G}. Spend this mana only to cast a creature spell of the chosen type or a legendary creature spell.

As Mirror of the Forebears enters the battlefield, choose a creature type.

{1}: Until end of turn, Mirror of the Forebears becomes a copy of target creature you control of the chosen type, except it's an artifact in addition to its other types.

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)

Mosswort Bridge enters the battlefield tapped.

{T}: Add {G}.

{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

As Obelisk of Urd enters the battlefield, choose a creature type.

Creatures you control of the chosen type get +2/+2.

As Pillar of Origins enters the battlefield, choose a creature type.

{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

As Progenitor's Icon enters the battlefield, choose a creature type.

{T}: Add one mana of any color.

{T}: The next spell of the chosen type you cast this turn can be cast as though it had flash.

As Secluded Courtyard enters the battlefield, choose a creature type.

{T}: Add {C}.

{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Whenever a creature with power equal to its toughness enters the battlefield under your control, you may pay {1}. If you do, draw a card.

As Unclaimed Territory enters the battlefield, choose a creature type.

{T}: Add {C}.

{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Whenever a creature enters the battlefield, if you cast it from your hand, you may search your library for a creature card with the same total power and toughness, put it onto the battlefield, then shuffle.