Guinea Pig 6: Mermaid in the Manhole(ザ・ギニーピッグ マンホールの中の人魚)

An artist finds and rescues a mermaid in a sewer. He takes her home with him and she develops sores all over her body that begin to pustulate and bleed. He uses what oozes from her sores to paint her portrait. When he can no longer handle it anymore he breaks down and dismembers her body.