What Fizz Ult Hitbox does
Fizz's ult lands at a target location. Then it swims around in a small circle from that location and attaches onto an enemy champion if it's found. It also grows based on the distance traveled, the small circle at it's landing point included. That is why Fizz's ult hitbox seems broken, when it's really not.
Am I saying it should be this way or am I calling for nerfs? No.
I am simply pointing out what it actually does so people can stop complaining about how overly broken the hitbox is when it lands next to them.