ok, so that's how I see it:
DoT like any other poison (1) in game, but it's passive bonus damage in autoattacks with good ap ratio, additionally works like minimalised version of Garren's Demacian Justice (2)
Fizz has passive physical damage reduction like Amumu (3) (but stronger)
He jumps and dashes like Riven (4) or Renekton but much further and he is untargetable like Vlad in his blood pool (but Vlad has longer cooldown and he loses hp on use) (5) or Yi on Alpha Strike (but Yi must target enemy minion/champion)
In theory, Fizz tosses fish, but in practise he's tossing Ulting Malphite (but with lower cooldown and with bigger damage)
Great job Riot! Another balanced champion!! -_-'