Tiller of Flesh is a uncommon Creature — Phyrexian Knight card from March of the Machine (MOM), collector number 44. Current market price: $0.21 (foil $0.15), TCGplayer market prices via Scryfall.
Whenever you cast a spell that targets one or more permanents, incubate 2. (Create an Incubator token with two +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)