He is a giant reindeer   


He was in the tundra searching for a yeti but the hunt was futile but then on the way back his car crashed and the yeti just appered then a punched him sending him flying and he landed on top of a mountin but after a few days he had eaten all his food but one Scum Ultra but i was frozen so he broke the can and eat it as the recuse team came and took him to a plane back home but once to almost to his home he began transforming with his hads becoming hooves he fell to the floor of the plane as horns grew from the sides ofd his head then he grew and broke windows of the plane making it go down but a fully transformed Rolf hopped out and landed in the city and he started smashing everything he saw as he was full of rage.   


He uses his antlers to push down buildings and he`s  fast  and  gets  on  all  fours  and  charges  in  rampage   mode.