Apex Devastator is a mythic Creature — Chimera Hydra card from Magic Online Promos (PRM), collector number 86000.
Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)