Rarely, but I've heard of it happening before. The kind that hitchhike I don't be believe are as venomous as the fish eating ones found in the wild. They're not strike on sight animals either like mantis, sharks, etc.. you would have to be trying to get speared or getting a good look at it holding the shell for anything like that to happen. I haven't read up on cones is awhile, but the last thing I read mentioned only 15 deaths via snails.