PJ is an Easy Allies troll emote depicting the face of a Nintendo Mii avatar.
Ben took his Nintendo 3DS on an airplane but accidentally left it there. When he went back to retrieve it, the 3DS was already gone. Later, he discovered that his Mii had been changed by, who he assumes is, some kid named PJ. After Ben told the story during their One-Month Celebration stream, PJ forever became part of Easy Allies lore and was immortalized as a Twitch emote.
A Win For Anime • Anime Books