Geralf, Visionary Stitcher is a rare Legendary Creature — Human Wizard card from Innistrad: Crimson Vow (VOW), collector number 61. Current market price: $0.98 (foil $1.11), TCGplayer market prices via Scryfall.
Zombies you control have flying. {U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.