Although Peacemaker tends to verbally abuse everyone around him more or less constantly, the member of his team who definitely gets the worst of it is John Economos (Steve Agee). In their first scene together, Peacemaker makes fun of Economos' beard, saying it looks dyed. John vehemently denies this, and its clear that Peacemaker's words have really hurt him, but Peacemaker doesn't let up one bit. Throughout the rest of the season, Peacemaker mocks Economos relentlessly, calling him "Dye-Beard" countless times.
If that wasn't bad enough, all this takes on an additional layer of melancholy when we learn a bit more about Economos in the season finale. Economos has gone undercover, pretending to be an alien "Butterfly" that is possessing a human body, when one of his "fellow aliens" asks him, "The man you've taken over. Why did he do that to his beard?" In order to not break his cover, Economos is forced to admit, "He thought it made him look younger and more handsome. He never had a girlfriend, so he thought dyeing his beard might help." Peacemaker, who is listening in, winces in pain, perhaps finally realizing that his repeated teasing was genuinely hurtful.
Peacemaker does a lot of terrible stuff over the course of the first season, including a ludicrous amount of murders, so making fun of his friend's beard isn't topping the list of his worst offenses, but nonetheless, it's still a real jerk move.
