Beta and Gamma are Alpha's lieutenants. Beta is a Rottweiler and Gamma is a Bulldog. Like their boss Alpha, they both wear translation collars that enable them to talk. They were sent on a mission to find a giant bird and bring it to their master, although Dug was initially assigned this task because he was a disgrace to the pack, and they wanted him gone.
Beta and Gamma later encounter Carl Fredricksen, Russell, and Dug. After some conflict, they take the trio of misfits to their master, who turns out to be an elderly Charles Muntz, Carl's childhood idol. Inside the dirigible, numerous photos, drawings, and information on Kevin (the bird) can be seen. Carl soon realizes what is happening; Muntz is searching for Kevin. Carl hastily rushes Dug and Russell outside. Beta, Gamma and the pack immediately give chase after understanding why they suddenly left.
Beta and Gamma are later seen driving biplanes. Outside, Russell sees Carl and Kevin in trouble. Encouraged, he manages to climb to the porch of the house. Planes continue to attack, but he manages to stop the planes by calling out that he sees a squirrel; this distracts Beta and Gamma (and another dog) and makes them collide all of the planes, though the dogs parachute to safety.
Beta and Gamma are briefly seen playing poker on a card table in Muntz's Spirit of Adventure airship.
Beta and Gamma are last seen among the other dogs at Russell's ceremony. They howl with approval after Carl awards Russell the grape soda badge from his deceased wife Ellie. Presumably, Beta and Gamma become the pets of residents at the Shady Oaks Retirement Home after Dug took over as "Alpha."
Dug's Special Mission
Beta, Gamma and Alpha are tripped by Dug, causing them to lose Kevin. When Alpha gives Dug "special missions," Beta and Gamma show support, but get hurt along the way and almost killed. They all eventually leave Dug, with Alpha calling him a bad dog.
- The dogs who are seen playing poker is a tribute to the famous Dogs Playing Poker series of paintings by Cassius Marcellus Coolidge.
- Beta and Gamma are Greek letters of the alphabet, along with Alpha.
- Although it is unknown how Beta and Gamma got back on the blimp when they parachuted to safety from their biplanes, Carl, Russell, and Dug might have picked them up while they were returning Kevin to her babies.