Fish was created at the creation of the galaxy to help Theo create everything.
After Theo and Fish created the galaxy the galaxy Fish went to Ollieland to study. He became a scientist and made his bowl advanced by ading arms, legs and a propeller so he can fly around a make more things.
Fish returned to Theoland after Sandy was created to look after him. Much to fish's disliking Sandy calls Fish clone. Fish often carries Sandy around as he is very strong.