Robo-Dog was a robotic dog and an antagonist in TV show Lazytown. Robo-Dog met his end when Stephanie managed to turn him off by flipping the switch on his back.
It was created by Robbie Rotten to help him fight Sportacus and chase the kids away, but it was programmed attack anyone that said the word 'trouble'. During its initial training, Robbie seemed to enjoy toying with it, repeatedly shouting 'trouble' and then crouching just out of reach while it yipped and snarled from the edge of its chain.
However, when Sportacus takes a vacation, Stephanie takes it upon herself to protect Lazytown as SportaStephanie. Robbie unleashes the dog on the town, which causes mayhem until Robbie accidentally says 'trouble', causing the dog to attack him as well. Robbie was saved by Sportacus, who returned and stopped the Robo-Dog. Robo-Dog was last seen sleeping on Robbie's chair, while Robbie was forced to sleep in the kennel he had built for his robotic pet.