(Not enough room for a good title so sorry about that. Sorry for the TT in targeted, too)
This would include tower shots, Veigars ult, Karthus' ult. tristana's charge and many more.
It's honestly disgusting how well this guy can avoid these kinds of damage. Especially disgusting with how amazing it makes him at tower diving.
Of course, compensation buffs would be needed - but Fizz actually being able to do this is outright toxic.