Oracle Text

Creature — Possum Mount

Whenever this creature attacks while saddled, it gets +1/+2 until end of turn. Then you may return any number of creatures that saddled it this turn to their owner's hand. Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)