Phyrexian Vatmother is a rare Creature — Phyrexian Horror card from The List (PLST), collector number MBS-52. Current market price: $0.86, TCGplayer market prices via Scryfall.
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.) At the beginning of your upkeep, you get a poison counter.