I made a toy out of a plastic button and some thread, and it's a hit with everyone. Ratchet is completely vicious with it and Frog likes to chase it. Moonshoes likes to look at it, but if it moves he wants nothing to do with it.
My sister's sorority likes to follow it around and bite it, her veil tail likes to flare at it, and her halfmoon with a tumor flares at it and chases it until it's out of his tank.
Hopefully this will encourage Ratchet to stop his tail biting and wait for playtime. He's also decided that pushing and biting the yellow bottle cap is ok.