Og ind i bjørnens mund
Would "hopped" not translate also?
-(e)t and -de are normal past tense endings on Danish verbs. -ed does not exist as a verb ending as far as I know
I have a feeling this was a question about the English sentence, which I have added "hopped/was hopping" as an option now
Hopped would imply the fish had grown legs; I would expect to hear it used in a sentence about frogs or rabbits. Jumped or leapt/leaped are probably more appropriate for fish. (native British English speaker)