Creature — Wall
Pitchstone 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.
From Magic: The Gathering.
Exact printings
Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o2s360rmvpb1hcon0n2hu.