Avatar: The Last Airbender Promos

Creature — Human Rogue Ally

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Tap an untapped Ally you control: Exile target card from a graveyard.
Whenever this creature attacks, you may cast an Ally spell from among cards you own exiled with this creature.

Boiling Rock Rioter

Avatar: The Last Airbender Eternal

Food

Legendary Creature — Bear

When Bosco enters, create a Food token for each legendary creature you control. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{2}{G}, Sacrifice a Food: Put two +1/+1 counters on Bosco. He gains trample until end of turn.

Bosco, Just a Bear

Avatar: The Last Airbender

Spirit

Creature — Human Druid Ally

Lifelink
Whenever you draw your second card each turn, create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."

Foggy Swamp Spirit Keeper

Creature — Human Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Firebending X, where X is this creature's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)

Firebending Student

Final Fantasy

Creature — Human Soldier

When this creature enters, mill three cards and you gain 3 life. (To mill three cards, put the top three cards of your library into your graveyard.)

Shinra Reinforcements

Bloomburrow

Cragflame

Legendary Creature — Mouse Soldier

Other Mice you control get +1/+1.
When Mabel enters, create Cragflame, a legendary colorless Equipment artifact token with "Equipped creature gets +1/+1 and has vigilance, trample, and haste" and equip {2}.

Mabel, Heir to Cragflame

Secret Lair Drop

Sorcery

Destroy each artifact with mana value X or less.

Meltdown

Creature — Cat Beast

When this creature enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.