Robert "Robbie" Stacey Valentino is the most recurring antagonist in Gravity Falls. He's best known as Dipper's love rival for Wendy. He is the tertiary antagonist, later anti-hero of Gravity Falls.
He is voiced by T.J Miller.
Robbie is first seen riding up with Wendy's other friends to pick her up. He is then seen as they drive to the Dusk 2 Dawn convenience store. During the group's stay at the store, he acts very condescending towards Dipper. He makes fun of Dipper when he hesitates to jump the gate, and doesn't think Dipper can get them inside the store when Robbie's efforts to open the door prove to be pointless. Once Dipper gets the kids inside, he is seen partying with the rest of them. Once the ghosts attack, he is one of the only teenagers not to be taken. However, he is not seen when Dipper does the Lamby Lamby Dance to save the group. He next appears in "Double Dipper" at the Mystery Shack party hanging out with Wendy. He ignores Dipper and shows Wendy his new guitar. Seeing him as an obstacle between him getting to dance with Wendy, Dipper and his clones lure Robbie away from the party by stealing his bike away from him. However, at the end of the episode, Robbie comes back and chats with Wendy, ruining Dipper's plan.
He starts dating Wendy in "The Time Traveler's Pig", which sets up the plot for Dipper to start time traveling to prevent it. Later when Dipper successfully wins Wendy a stuffed animal, Robbie becomes jealous and walks away, trying to not care. When Mabel's enemy, Pacifica Northwest, took Mabel's pet pig, Dipper decides to time travel back again after he realizes he'll break Mabel's heart if he doesn't. This makes Robbie date Wendy in the present time. At the end, he gets embarrassed by a bunch of people. And everyone laughed at him.
In "Fight Fighters", Robbie notices Dipper's crush on Wendy, and he tries to call Wendy to tell her Dipper's secret. However, Dipper breaks Robbie's phone to prevent this from happening, causing Robbie to challenge Dipper to a fight at 3:00. When Dipper unleashes Rumble McSkirmish from an arcade game, Dipper uses Rumble as a bodyguard to scare off Robbie and put a stop to the fight. When Rumble encounters Robbie, he nearly kills him. Dipper tries to stop Rumble from seriously injuring Robbie, and he successfully does so by facing Rumble in a battle. Robbie decides not to fight Dipper afterwards, and the two decide to hate each other in silence, rather than to physically show their anger.
Robbie has long black hair with pale skin and piercings. Like some characters on Gravity Falls, he has a pink nose. He wears a black guitar around his chest. His pants are blue with silver keys attached to his belt loop. He wears tight pants which is overrated. He also wears a black hoodie with a picture of a red bleeding heart with a scar on it. He also wears black fingerless gloves and has pimples on his face. He has two strands of hair on his chin.
In terms of personality, Robbie is a stereotypical teenager: Laid back, carefree, and fun-loving. He is seen as condescending to people younger than him, as shown by his interactions with Dipper. In "The Time Traveler's Pig," he asks Wendy to go out with him and she agrees, right in front of Dipper.
- Robbie's voice actor is T.J. Miller, who is the voice of Tuffnut from the movie How to Train Your Dragon.
- In "Double Dipper", Dipper clones 3 and 4 stole Robbie's bike, but didn't return in the episode.