This probably wont go anywhere, but i think it would be sweet to have fizz's ult hook-able to prevent it from hitting a squishy carry. It's relatively fast moving, so it getting hooked might take a little bit of skill, and might relieve the pain of its seemingly massive hitbox. Just think it would be a cool interaction. That is all.
It already has enough interaction imo in the fact that it's at least a dodgeable skillshot. Giving even more "counterplay" opportunities to adcs against assassins sounds like a horrible idea.
If you think now it's bad, it was worse
I feel Fizz's ult is interactive enough, due to it being a skillshot that needs to be applied from a distance to be powerful, so if Fizz needs more interactivity (and I personally think he does), that might not be the best place to put it. Additionally, making the fish vulnerable to displacements could be troublesome in an environment where many more abilities than just hooks can readily displace targets, and if the intent is to enable just hooks on it, that risks making the interaction too specific.
