Logan Grimnar
Logan Grimnar is Chapter Master of the Space Wolves, and all-around cool guy. He has been the Space Wolves Chapter master for over 700 years and has been kicking ass even longer, making him one of the oldest Chapter Masters currently serving. He has shown great battle prowess and his thirst for blood rivals that of their mighty Primarch, Leman Russ. As such, he is said to be the greatest living warrior in the Imperium. (Suck on, Calgar) Grimnar wears a pimped out suit of terminator armour equipped with a storm bolter and carries his trusty axe Morkai (which he got from beating the shit out of a Chaos champion and stealing it from him, then beating the corruption out of the daemon weapon until it submitted to him) into war with him. As of the 5th Ed. Space Wolf Codex, he also has the ability to buff his squad with some fun tricks, give all nearby allied models an extra attack for one turn, AND makes Wolf Guard into a Troops choice, allowing you to pimp out your whole army. Isn't he generous? Well, he's certainly generous to the enemies of the Imperium - WITH THE ASS-KICKINGS!
The Ecclesiarchy does not like him, and has charged him on multiple counts of treason and heresy for being a decent person to the Imperial Guard and other non-Astartes organizations. Like after the Armageddon War (in which he actually managed to make Angron even ANGRIER), when those assholes decided to purge all the Guardsmen who fought there because they were "tainted" or some shit and Grimnar called them out on their dickery.
And he also shares the same resentment towards the Dark Angels as the rest of his chapter (Where's the fluff on this, exactly? He probably does, though. Bathrobe-wearing pansies.).
He is the only known furry that you can think is FUCKING AWESOME without being HERE-BLAMMED.