Cthulhu, Titan of the Deep

When Cthulhu enters the battlefield, sacrifice it unless it escaped.

If Cthulhu is in the graveyard you may cast Kraken, Leviathan, Octopus, and Serpant spell from your graveyard and those spells cost {5} less to cast.

Escape—{u}{u}{b}{b}, Exile five other cards from your graveyard. (You may cast this card from your
graveyard for its escape cost.)