Change Nunu's movement to a hopping mechanism like Kalista, except no need to auto.

I think it would fit his character as being an awkward non-conventional champion that is intimidatingly simplistic, adding depth to that eccentricity without disrupting his overall linearity. You can set paths to a destination, and he would go there taking the traditional unobstructed path, while hopping. But his hops should be able to jump over the same structures that the Kalista hops can, so if Nunu wanted to run from the Red side blue buff to the bottom lane river bush, he could jump over the small ledge without the bomb plant. And this would just the way he moves, so there's no cool down like Talon's parkour abilities, or riven's Q-based jumps. This major expansion of his mobility would allow him to be a much more flexible ganking jungler rather than purely just an objective control-freak. His hops will help him get into the right positions without being revealed by standard enemy ward locations and allow him pull off nasty Empires when the approaching enemy least expects it. Jarvan, Khazix, and many other jungles are feared for their ability to easily surmount geological infrastructures, avoiding detection by spotty jungle wards, which results in ganks with the full element of surprise. As a jungler, Nunu should at least be allowed to move across the jungle extremely flexibly to be in position for optimal gank moments since ganking windows for him are so incredibly slim.

ALSO, I feel we can do better with his W, blood boil, than just a brain-dead ap/as stat buff. I understand he is a supportive jungler, but he can bring that to the game in a much more interesting way. Instead of increasing damage, CC that causes chaos amongst his enemies, an AOE slippery ice spell that mimics Cassiopeia's Miasma which takes away dashes and flash abilities, as well as a minor slow, but also makes enemies slide in a straight line based on the intial vector of their movement when they enter the ice field, or when it is casted underneath them. In an extremely tight situation where many champions (especially melee champs) are hugging each other, trying to kill a squishy target, nunu can cause an ice floor to send enemy champs into limited straight-line movements across the ice field, making out-maneuvering them easy.