Crabby thing

Spent some time in Rosemarkie on south coast of Black Isle. There was a brief shower when I got there and when it stopped got a shot looking east down Moray Firth with a good rainbow. As tide was on its way out walked along the beach looking at the rock pools. Still haven't lost my fascination with these things that I had as a kid (a bit like steam engines). But realize I've got to an age when I've got to be more careful - a twisted ankle and a drowned camera isn't what I need. Saw this creature and got a picture of sorts. Think it could be a hermit crab but I'm not sure.