Kog Maw
In my opinion, Kog Maw needs to be balanced. I haven't come across a hard carry Kog through the bot lane lately, but through the jungle is where I have seen him hard carry. Slap a Bloodrazer, add attack speed and lifesteal trough items like BoRK, Runaan's, etc., and the game is just swayed like the parting of the ocean. It's just not fun to come up against. LoL would be in its perfect state if the game was fun for everyone at every stage of the game.