Stormsplitter is a mythic Creature — Otter Wizard card from Bloomburrow Promos (PBLB), collector number 154s. Current market price: — (foil $3.70), TCGplayer market prices via Scryfall.
Haste Whenever you cast an instant or sorcery spell, create a token that's a copy of this creature. Exile that token at the beginning of the next end step.