Ravenous Squirrel

Whenever you sacrifice another creature or artifact, put a +1/+1 counter on this creature.

, Sacrifice an artifact or another creature: Put a +1/+1 counter on this creature.

Whenever a player sacrifices a creature, you may put a +1/+1 counter on this creature.

When this creature enters, put a +1/+1 counter on target creature and you gain 1 life.

Whenever a creature you control explores, put a +1/+1 counter on this creature and you gain 3 life.

, Sacrifice another creature or token: Draw a card. Activate only as a sorcery.

, , Sacrifice this creature: You gain 3 life.