Nunu and his Q
Now I love Nunu, he is an amazing jungler and god help you if he decides to take a detour through your jungle. But his Q I feel could be changed, currently Nunu has only two damaging spells, his E and his ult which is nice but if you're caught that's not helpful. I feel his Q should do regular magic damage to champions, it doesn't even have to heal him but I feel his Q should be there in case he needs it, if he can take a chomp out of baron I feel he can take a chomp out of that Katarina at mid.
Also this would help his ganking potentional, he walks into a lane E's the champion then takes a bite. It would make Nunu much more viable. Please Riot just think about it.