Fumulus, the Infestation is a rare Legendary Creature — Vampire Insect card from Foundations Jumpstart (J25), collector number 42. Current market price: $7.04, TCGplayer market prices via Scryfall.
Flying, deathtouch Whenever a player sacrifices a nontoken creature, create a 1/1 black Insect creature token with flying. Whenever an Insect, Leech, Slug, or Worm you control attacks, defending player loses 1 life and you gain 1 life.