Conversation so far:
what is the fishes name from cat in the hat
The fish's name is revealed to be Carlos K. Krinklebine in the TV special The Cat in the Hat, while he had no name in aaptations of the book.
what is the  fishes name from the cat in the hat book
He had no name in any of the other adaptations of the book, in which he was just called 'Fish'.
what does the fish in cat in the hat represent
In an analysis of the fish, MacDonald asserts that it represents the voice of the children's absent mother.

Question: how did the author come up with the book
Self-contained rewrite: how did dr. seuss come up with the cat in the hat