Festering Newt is a common Creature — Salamander card from Magic 2014 (M14), collector number 98. Current market price: $0.11 (foil $0.50), TCGplayer market prices via Scryfall.
When this creature dies, target creature an opponent controls gets -1/-1 until end of turn. That creature gets -4/-4 instead if you control a creature named Bogbrew Witch.