What is a Nembrotha nudibranch?

I’m so  common.  Literally.  Whenever I come to sign up to anything my name has always been taken, so I needed to think of something else I could use.  I’ve been diving 18yrs now and nudibranchs have always been the top of my list, so here it is, a fat warty old seaslug/nudibranch called Nembrotha