I recently had a Yuma start to move around on a frag plug and decide it wanted to go onto the rock scape. I noticed 2 small green mouths. They look like smaller versions of the mouths on the Yuma. Are these babies?
They will either “walk” around, dropping babies along the way, grow another mouth (or more sometimes) and get big and split, or they will just keep growing and refuse to do either. Looks like you got a walker.