Spark Double is a rare Creature — Illusion card from Marvel Super Heroes Commander (MSC), collector number 337. Current market price: $8.60, TCGplayer market prices via Scryfall.
You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.