Rebellion of the Flamekin is a uncommon Kindred Enchantment — Elemental card from Lorwyn (LRW), collector number 188. Current market price: $0.12 (foil $0.35), TCGplayer market prices via Scryfall.
Whenever you clash, you may pay {1}. If you do, create a 3/1 red Elemental Shaman creature token. If you won, that token gains haste until end of turn. (This ability triggers after the clash ends.)