Spoilers ahead for Chilling Adventures of Sabrina Season 3. The Chilling Adventures of Sabrina is just as much about high school teen romance as it is Satanic witch covens, and in Part 3, Sabrina's friend Theo finally gets a love interest of his own. When new student Robin rolls into town with a mysterious carnival, he and Theo become fast friends. Shy, soft-spoken, and always hidden under a red cap, Robin eventually reveals that he's a member of a pagan coven, and is actually a pointy-eared hobgoblin "who can run fast." He's not as powerful as Pan or the gorgon, but Robin's powers are still just as fantastical and important as the rest.
While Sabrina and her friends are at first distracted by their triple date to the carnival, it's Roz who first notices something is off about the place. Her cunning shows her that the ringleader isn't a man at all but the horned god Pan; the woman who reads tarot cards is Circe; and the peep show dancer is actually a gorgon, whose gaze turns any person to stone. They're all members of a pagan coven, which were wiped out by Satantic covens, like Sabrina's, ages before. It's Robin who eventually lets everyone in on their plan: now that Lucifer is imprisoned, they're here to destroy the mortals and resurrect their great god the Green Man.
Robin admits to Theo that he originally got close to him because in order for the Green Man to awaken, it needs the body of a virgin, and somehow there are only three virgins in the entire town of Greendale to sacrifice: Harvey, Theo, and Ms. Wardwell. Robin begins to truly fall for Theo though, so he defects from his family and teams up with Sabrina and the rest to thwart the pagans. It's a good thing he's on their side, too, because he saves Theo, Harvey, and Roz at a key moment: when the pagans storm Baxter High, Robin uses his unnatural speed to whisk each of them to safety and buy them some time.
Robin being able to run fast seems like a not-so-great power in the face of warring gods and demons, but in actuality his real value is in what he is: a Robin Goodfellow, which is defined by Merriam-Webster as "a mischievous sprite," also known as a puck. Puck, hobgoblin, and Robin Goodfellow have all been used interchangeably in English folklore to refer to a playful sprite or fairy, with the most well-known one being Puck in Shakespeare's A Midsummer Night's Dream. Puck is a quick-witted creature who delights in playing pranks, and it's because of his actions that nearly all the misunderstandings occur during the course of the story. He describes himself as a "merry wanderer of the night" — essentially a trickster who's not totally benevolent, but not actually malicious either. The line of "Those that Hob-goblin call you, and sweet Puck, / You do their work, and they shall have good luck" suggests that Puck, like CAOS' Robin, is actually longing for connection, and those that call upon him and treat him well end up getting gifts in return. (In folklore, a gift from a puck often means he'll clean your house at night, which honestly sounds like a great deal.)
Robin's hobgoblin nature is why it makes sense that he ultimately sides with Sabrina and her friends. Hobgoblins may enjoy some chaos and mischief, but they're ultimately considered domestic creatures who develop loyalties to those who show them kindness. Theo and the rest treat Robin better than his adopted family of pagans do, so when he hears that Pan is planning a horrible death for all of them, it's easy for him to switch loyalties. Sure, Robin's running ability might not stand a chance against any demonic entities in the future, but it certainly never hurts to have more magical friends watching your back.