Is there any item that can negate fizz's ultimate?

I think you can quick silver sash active the effect off you, but the shark will still jump in the area casted so I wouldn't stand there.

pretty sure banshee's works like qss in that the fish doesn't stick to you and you still have to move out of they way.

Zhonyas can block it

qss or zhonya's

So yeah QSS, Zhonyas, and Banshee's, pretty easy to fit into most builds.

cleanse can remove it but you still have to stand out of its way when it bites.

QSS then, which builds into Mercurial.