Jund is a common Plane — Alara card from Planechase Anthology Planes (OPCA), collector number 41. Current market price: $1.36, TCGplayer market prices via Scryfall.
Whenever a player casts a creature spell that's black, red, or green, it gains devour 5. (As that creature enters, you may sacrifice any number of creatures. It enters with five times that many +1/+1 counters on it.) Whenever chaos ensues, create two 1/1 red Goblin creature tokens.