Pest? PEST?? I am clearly lacking in taste and discernment as this looks quite gorgeous to me. Sort of frogspawnish, with overtones of liposuction.
I assume that "pest" means it spreads too easily. How hard is it to remove if it becmes too enthusiastic or moves into a space you don't want it? Are we talking aptasia level, nuke it from orbit just to be sure difficult, or can you just grab, yank and that particular bundle goes to majano heaven? (ie flushed or compost heap or whatever you do with unwanted corals)
Or does it have more insidiously evil habits that put it in the pestworthy category? Stinger spines? Flatulence? Tendency to burst into song and demand feedings of blood? (yes I have watched "Little Shop of Horrors" a few hundred too many times.) Just curious.