Fabulous Fish adds a whole bunch of weird fish stuff. Cut fish into fish heads to create things such as the Fishtober, which rains fish when you use it because why not? Or, if you're more sensible, you can craft it into the incredible Fishtober Star, a powerful thrown weapon of destruction. You can also cut them into fish shards which can be smelted to create fish ingots, which can be eaten or turned into fish tools (they spawn cod when you use them).