Stormscale Scion is a mythic Creature — Dragon card from Tarkir: Dragonstorm Promos (PTDM), collector number 123s. Current market price: — (foil $6.00), TCGplayer market prices via Scryfall.
Flying Other Dragons you control get +1/+1. Storm (When you cast this spell, copy it for each spell cast before it this turn. Copies become tokens.)