Decorator crab, Achaeus spinosus
Typically, decorator crabs attach pieces of sponge and seaweed to themselves to camouflage and hide from predators (which makes them very poor photographic subjects). However, Achaeus spinosus attaches stinging hydroids to itself to ward off potential predators (making it a very attractive subject for photography).
Lembeh Strait, North East Sulawesi, Indonesia
Canon EOS 7D Mk II, Canon EF 100mm, f/2.8 macro USM, 1/250, f/16, ISO 200, INON Z240 strobe with Retra Pro light shaping device, handheldby Ross Gudgeon, Western Australia