Nibbler Week!

So the Nibbler makes it to the fishtank castle and his followers are there. They have a regeneration machine to help repair him. But it makes him into an evolved (big-brain) version of himself while it repairs his body...

The follower heads were included with some Winter Nibblers (or all of them - I'm not sure. I got a bunch of these second hand). The Future Nibbler was offered a few times, and should remind you of something from British television.