Whether I’m walking in a rainforest or floating over a coral reef, I love seeing unusual creatures that appear to be from another planet. This is a crested nembrotha, which is a type of nudibranch (sea slug). It’s easy to imagine a giant spacefaring version of this nudibranch attacking a red-shirted crewman in an old Star Trek episode.
Photographed last month in the Raja Ampat region of Indonesian New Guinea.