(Seafloor Wreckage isn't a spell.)

Whenever Seafloor Wreckage becomes tapped, it deals 1 damage to you.

Discard two cards: Put a 2/2 black Zombie creature token onto the battlefield.

, Pay 1 life, Sacrifice Seafloor Wreckage: Search your library for a Island or Swamp card and put it onto the battlefield, then shuffle your library.