"The Bone Leech is a small, worm-like parasite. A fairly weak creature, its power comes from its ability to infest and take over other creatures, providing it with a means of protection, a more effective way to attack, nourishment as it grows, and most importantly, a breeding ground for more Bone Leeches."--Blood II: The Chosen Manual
The Bone Leech is a nuisance enemy from Blood II: The Chosen. It is a face-sized parasite resembling a leech or eel with pincers protruding from its flesh, originating from Reality Beta. It infects by attaching to the victim's face and inserting its pincers. The victim either loses consciousness or dies, at which point the leech enters the chest and attaches to the spinal nerves. At this point the leech takes control and metamorphoses the body into the stages of Soul Drudge, Drudge Lord, and finally Drudge Priest. They are often found in bathrooms, pools of water, sewage, or other fluids. It is unclear if they evolved to take over similar humanoids from their home dimension, who possibly built the architecture in C4L1: Beyond the Rift.