Robin's fangirls are teenage girls with an obsession over Robin.
After Robin accidentally locked himself out of Titans Tower without any clothes, he attempted to reenter the tower, but spotted four of his fangirls crowded in front of the door. Upon spotting him, the fangirls squealed in delight and chased him around the island while they took pictures of him. He eventually made his way to the laundry room window where he knocked on the glass to get Raven's attention in an attempt to be let in to the tower and away from his fangirls. However, she refused to help him which allowed one of the fangirls to take a picture of Robin's nudity.
Teen Titans Go! comic book series
After Robin decided to become a teen pop sensation to impress Starfire, he attracted several other fans as a result, including Terra. However, they proved to be a hindrance as they constantly interrupted the Titans whenever they prepared to battle villains. Eventually, Robin became annoyed by the attention but reassured himself that he had won Starfire's heart. He then noticed that Starfire and his fangirls had become attracted to another teen pop idol, Scooter. Angered, Robin proceeded to attack him.