Yeah, the more I read this thread and research, I don’t think this is a whelk anymore. Melev’s reef mentioned those two features as well, which he doesn’t have. Somewhere else mentioned the dark shells which are definitely in the list poster’s pic but my guy has a pretty light shell. He’s actually a really pretty, bright white all over his body/foot. I’m going to keep an eye on him for now. As I mentioned, I didn’t even know it was alive until today lol. He climbed the glass right after I did a water change & actually moved pretty quickly like a nassarius. If he starts bothering my corals, into the sump he goes!