The Caribbean reef squid’s (Sepioteuthis sepioidea) tentacles and head are made up almost entirely of muscle. They use these muscles to move fast, escape predators, and capture prey. On top of their already impressive athleticism, Caribbean reef squids also have some of the largest eyes relative to their body size of any animal in the animal kingdom!
Sketch contributed by Hee Jin Chung. Fact contributed by Allison Lau.
[Edited by Allison Lau]
Source: Kier, W. M. (1982). The functional morphology of the musculature of squid (Loliginidae) arms and tentacles. Journal of Morphology, 172(2), 179-192.