Gu (simplified Chinese: 蛊; traditional Chinese: 蠱; pinyin: gǔ; Wade–Giles: ku) or jincan (simplified Chinese: 金蚕; traditional Chinese: 金蠶; pinyin: jīncán; Wade–Giles: chin-ts'an; lit. ""gold silkworm"") was a venom-based poison associated with cultures of south China, particularly Nanyue. The traditional preparation of gu poison involved sealing several venomous creatures (e.g., centipede, snake, scorpion) inside a closed container, where they devoured one another and allegedly concentrated their toxins into a single survivor. Gu was used in black magic practices such as manipulating sexual partners, creating malignant diseases, and causing death. According to Chinese folklore, a gu spirit could transform into various animals, typically a worm, caterpillar, snake, frog, dog, or pig.