Chittering Skitterling is a uncommon Creature — Phyrexian Rat card from Phyrexia: All Will Be One (ONE), collector number 87. Current market price: $0.27 (foil $0.25), TCGplayer market prices via Scryfall.
Corrupted — Sacrifice an artifact or creature: Draw a card. Activate only if an opponent has three or more poison counters and only once each turn.