Sakashima's Student is a rare Creature — Human Ninja card from The List (PLST), collector number PCA-24. Current market price: $17.70, TCGplayer market prices via Scryfall.
Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) You may have this creature enter as a copy of any creature on the battlefield, except it's a Ninja in addition to its other creature types.