The Sea Leech is a monstrosity whose taxonomic classification remains unknown. It widely varies in appearance, with no two sea leeches looking alike. Of those observed so far, all manner of tentacles, fins, arms and legs, and other appendages have been seen (although some leeches have no appendages at all). It averages 3 meters wide and 10 meters long. It has anywhere from one large mouth to ten mouths which it uses to feed.
Very little is known biologically about the Sea Leech, except in the manner that it feeds. It uses its muscular mouth to suck the blood out of a victim, which it entangles in its appendages. A sea leech can suck all of the blood from a metahuman in the span of five minutes. Most sea leeches seek prey in the water, and there have been no reported attacks above the surface of water. The traditional methods of extracting leeches, including fire and salt, are useful.
Parazoologists are divided as to the origins of the Sea Leech, whether it is Awakened, a genetic experiment gone horribly wrong, or toxic spirits trapped in a physical form. It is found primarily in the San Francisco Bay Area.