Cthulhu, the Great Dreamer

Islandwalk, swampwalk (This Creature can't be
blocked as long as defending player controls an Island
or a Swamp)
Whenever Cthulhu, the Great Dreamer deals
combat damage to a player, you may cast
target instant or sorcery card from that player's
graveyard without paying its mana cost.If that
card would be put into a graveyard this turn,
exile it instead.