Mike found this colorful creature completely by accident. His suncorals were somewhat closed up, and this polyp was on the move! Using tweezers, he removed this nudibranch. Odds are it is a Phestilla melanobranchia, a cup coral eating nudibranch. In this case, the animal ate suncoral tissue and as it did, its body matched the coloration of the coral fare. As he couldn't afford to buy Tubastrea to keep this little guy fed, it perished. Not Reef-safe.
Photos by Mike Olier
I hate to put this beauty in a Pest category, but it is what it is.