This plugin is supposed to add custom fish that you can find and fish in the world, but by popular demand, here's a skeleton release of it (technically hair release, because instead of adding very basic core features, I added some aesthetic ones) that adds two config options to tell players what they caught and to add the caught items directly to their inventory.
It technically needs PaperMC 1.18, but given what it has, it might work with earlier versions as well.
Only one command added currently, /fancyfish reload which reloads the plugin's configuration.