I have a Peppermint shrimp and it looks like it dances. He'll come out for food and it looks like hes waddling back and forth. Does that make sense? IT could just be another common name that their vendor calls it. I had a sexy shrimp and those look like they dance as well except they shake their "butts".
The dancing ones are not reef safe if i'm not mistaken but use caution I've heard people say they can munch on zoanthids but its just a risk thats up to you. LFS around me call them camel shrimp. I have a flame angel in my 75 with all zoanthids, sps and other softcorals and he doesn't eat them or pick on them.
a word of caution though, lysmata californica are also know as a peppermint shrimp and are sometimes mis sold. these are not suitable tropical marine tanks and will not live long at reef temps.