Ob Nixilis, the Fallen is a mythic Legendary Creature — Demon card from Iconic Masters (IMA), collector number 101. Current market price: $5.00 (foil $10.66), TCGplayer market prices via Scryfall.
Landfall — Whenever a land you control enters, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis.