Aquatic undead that scavenge shipwrecks and drownings, ambushing swimmers with paralysis and poisonous aura

Unlike the common ghoul which scavenges battlefields and graveyards for the rotten flesh they crave, Sea Ghouls adapted to scavenge the large bodies of water where shipwrecks and drownings are frequent. Their softer, water-softened flesh renders them immobile outside of the water, but they are fast and agile swimmers. They can only paralyze one medium-sized creature per day (save vs. Paralysis), but compensate in combat with an aura of poisoned water that surrounds them for 5 feet in all directions. Creatures in this aura must save vs Poison. Small fish found floating to the surface in a distinct path are a telltale sign of sea ghouls sea ghasts prowling below the surface of the water. They are ambush hunters, hiding among silt and plants for any lone or straggler swimmers in sight. They will approach from beneath, giving no warning other than the corpses of small fish floating to the surface where they move, or the sudden burning sensation as they make an unexpected save vs. Poison. Their poison aura dissuades interlopers as they paralyze their prey with a paralyzing bite, and drag the unlucky victim into the darkness to drown and soften. They favor deep, still water with silty