Arrby is shown to be nice and loving of Sid, his owner. Even though Arrby is good at heart, he is happy to assist him in stealing (or "fetching") items he wants to store in his ship, such as toys, televisions, guitars, and more. He is loyal to Sid often addressing him as Captain Boss Mr. Sid Sir. However he also tries to reason with Sid when his need to take things causes problems such as when the Shell of Puplantis was causing their ship to sink with the weight of the pearls it was producing. He also informs Sid when they have a lot of something he wishes to steal. He is friendly towards the Paw Patrol and mentioned them saving him when Sid's sub got trapped.
Arrby is a Dachshund, having dark brown fur and tan fur on his paws, underbelly, and muzzle. He has amber eyes. The structure of his head bears a slight resemblance to Zuma's, with the exception of his muzzle being slightly longer and differently colored, and his ears being a bit longer. Arrby wears a red and white striped cap, and a black shirt with ripped white sleeves and red and purple trim. His shirt is fastened by gold buttons, and his pup-tag is also gold and held by a red collar. He carries a small treasure chest on his back. His small stature causes him to move his paws quicker than other pups shown in the series as he walks.
For his scuba diving outfit, he wears a black wetsuit with gold trim and small red air tanks on his back, and a bubble helmet.