The name of the fish "Stör" is the same as the word "disturb". That alone offers a lot of potential for bad puns.
It is also weirdly common as a part of other words that don't have anything to do with fish. And third, there are parts of words that sound similar to Stör.
Take all those ingredients and you can have a lot of fun with strange word combinations and only native speakers have a realistic chance of understanding.