Groo The Wanderer #3 (Marvel Comics, 1985)

While wandering through the woods, Groo hears a cry for help and rushes forward to offer assistance. Groo does what Groo does best; he enters a fray and slays a bunch of enemies called Melenitas who appear to be attacking a nobleman. After being saved, the noble person gives Groo a medallion, which he claims makes Groo "one of us!"

Groo enters a nearby village where everyone scowls and glares at him, but Groo does not know why. Soon, he finds out why.

The guards accuse him of being a Hetita and threaten to throw him in prison. Groo fights them off and runs out of town, and then throws his medallion into the river.

He then walks by an outpost filled with guards who threaten him because he has no medallion, and that makes him a Melenita. They want to kill him for being a Melenita and attack. Outnumbered, Groo runs away and looks for the medallion in the river.

Meanwhile, the Melenitas attack the Hetita outpost and kill everyone. Groo returns to the outpost with the medallion around his neck. They beat him up because he is clearly a Hetita with a medallion.

After fumbling about, Groo enters a town where some where medallions and some do not. He throws away his medallion and enters a pub which, as it turns out, is a Hetita Inn! They chase him out, and this starts a civil war in the town after 50 years of peace under a Melenita and Hetita truce. Thanks, Groo!

At last, Groo is at peace once again. He hears a cry for help and saves a caravan from bandits. As a reward, they give him a ring, marking Groo as one of them, which causes Groo to lose his shit and chase the caravan out of the woods.