Splinter Twin is a rare Enchantment — Aura card from Modern Masters 2015 (MM2), collector number 129. Current market price: $7.61 (foil $23.49), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature has "{T}: Create a token that's a copy of this creature, except it has haste. Exile that token at the beginning of the next end step."