The Yeti crab (Kiwa hirsuta) live in what are called cold seeps, which are areas of the ocean floor where there is a plethora of sulfides and methane that seep from fissures in the ground. In order to thrive in these harsh conditions, Yeti crabs have an epibiotic relationship with bacteria that live on the hairy appendages of their arms. These bacteria help to convert the sulfides and methane into usable energy, and in exchange, the crab will help the bacteria grow by moving around.

Art by @Squidtoons

[Edited by Isabelle McDonald]

Reference:

Goffredi, S. K., Jones, W. J., Erhlich, H., Springer, A., & Vrijenhoek, R. C. (2008). Epibiotic bacteria associated with the recently discovered Yeti crab, Kiwa hirsuta. Environmental Microbiology, 10(10), 2623–2634. https://doi.org/10.1111/j.1462-2920.2008.01684.x