How about a penguin warrior that relies on body and flipper gestures and different noises to communicate instead of words? He would probably have sided with someone in the Freljord. He could function as a primary tank with the secondary role as a support - or vice versa, after all you did state that you wanted a support in your post.
Starting with some abilities, he (( I keep saying "he", I would assume it be male since Gunter )) could have a dash that looks like he's sliding on his belly that causes a short stun or bump upon hitting an enemy unit - enemy champ, jungle camps, minions? Then he could have a sword that when he uses another ability it knocks enemies away a short distance because he has short penguin flippers and that's hard to manage for a penguin, OKAY?! Then his third ability could be some form of buff to himself and/or those around him. Finally his ult could be something along the lines of, "BRING IN THE CALVARY!" where he starts dashing forwards with a ton of other penguins belly sliding behind him and knocking people up (( like a hecarim 
ult but instead of fear, a knockup )).
He'd probably have AP scaling on some abilities and AD on others - there is the opportunity to have hybrid, but that'd be more offensive than a tank - and benefit most from armor/MR instead of health. After all, you have to be tough to withstand the freezing winds of the Freljord, but that doesn't mean your big and tough like Braum!
Some interactions could be with all the Freljord champions. Particularly with Lissandra because she could be the Ice Queen (( Adventure time reference to the Fiona and Cake alt universe )). He might also have some fun interactions with Quinn (( or more specifically, Valor )) where they act like rivals.
Is this anywhere you were trying to go with this idea?
