Hermissenda crassicornis
Hermissenda crassicornis , also known as the Thick-Horned Nudibranch , is a species of brightly coloured , sea slug or nudibranch , a marine gastropod mollusc in the family Facelinidae . 
<triplet> gastropod <subj> mollusc <obj> parent taxon <triplet> Facelinidae <subj> nudibranch <obj> parent taxon