Thief of Sanity

Flying
Whenever this creature deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Flying
Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. For as long as that card remains exiled, you may look at it, you may cast it, and you may spend mana as though it were mana of any type to cast that spell.

The List

Outlaws of Thunder Junction Commander

Flying
Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Ravnica: Clue Edition

Flying
Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast it.

New Capenna Commander

Whenever an opponent casts a noncreature spell, create a Food token.
Whenever a creature deals combat damage to you, sacrifice a Food token.
Tap two untapped Foods you control: Add one mana of any color.