Deathtouch, islandwalk, swampwalk
While your opponent controls a creature whose toughness is higher than Sebek, Sebek is indestructible.
T: Put a 1/1 blue and black Crocodile Token with islandwalk into play.
A demigod of the Nile, Sebek can summon and control crocodiles at will, and has been known to swallow boats and living creatures whole.