Pitchstone Wall 
Creature — Wall
Defender (This creature can't attack.) Whenever you discard a card, you may sacrifice this creature. If you do, return the discarded card from your graveyard to your hand.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL