Looks like some forams are growing on its shell. Well-aged little biggerThis is my longest standing creature, it came in on a coral about 6 or 7 years ago because staff didn't notice it, inch and a quarter - half now, it is the only snail the tassle fill fish hasn't eaten except dove snails and cowries as it can't get into them, the tassle can't get at it due to snail super grip!