Feeling that the Canadians were using him as a weapon, Logan accepted Professor Charles Xavier’s offer to leave and join the X-Men, a group of mutant peacekeepers who fought for mutant rights. Instantly falling for teammate Jean Grey, Logan felt hostility towards her boyfriend and later husband, team leader Cyclops, with whom he frequently clashed due to Wolverine's rebellious nature and gruff attitude. Despite his shorter stature, Logan has a very burly and buff build. 