Plains

Valiant Changeling

This spell costs {1} less to cast for each creature type among creatures you control. This effect can't reduce the amount of mana this spell costs by more than {5}.
Changeling (This card is every creature type.)
Double strike

Impostor of the Sixth Pride

Changeling (This card is every creature type.)

Armillary Sphere

{2}, {T}, Sacrifice this artifact: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Coordinated Barrage

Choose a creature type. Coordinated Barrage deals damage to target attacking or blocking creature equal to the number of permanents you control of the chosen type.

King of the Pride

Irregular Cohort

Changeling (This card is every creature type.)
When this creature enters, create a 2/2 colorless Shapeshifter creature token with changeling.

Universal Automaton

Evolution Charm

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Return target creature card from your graveyard to your hand.
• Target creature gains flying until end of turn.

Regal Caracal

Other Cats you control get +1/+1 and have lifelink. (Damage dealt by those creatures also causes you to gain that much life.)
When this creature enters, create two 1/1 white Cat creature tokens with lifelink.

Marshal's Anthem

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Creatures you control get +1/+1.
When this enchantment enters, return up to X target creature cards from your graveyard to the battlefield, where X is the number of times this enchantment was kicked.

Howlpack Resurgence

Flash
Each creature you control that's a Wolf or a Werewolf gets +1/+1 and has trample.