The leader wears a brown leather jacket covering a white shirt, along with a black hat and blue pants with a large belt buckle. The second bear wears a black and white jacket and a black flat cap. The third bear wears a light blue jacket covering a dark blue shirt, and appears to have squinted eyes.
The bears enjoy playing cards and gambling at the nightclub, and are very serious about it. They also hate being cheated; when they realize Mike swindled them, they relentlessly chase him, and even try to eat him on multiple occasions.
The bears are swindled in a card game with Mike, but initially don't know that until the leader discovers a card peaking out of Mike's suit. After confirming their suspicions, they chase after Mike, but he manages to escape. Later on, the trio pass by the Moon Theater and notice Mike's car parked in front, they snatch up Mike during a phone call with his girlfriend, and learn that Mike already spent all of their money. The leader almost eats Mike, but the mouse tells them they can get $100,000 from Buster Moon.
They trespass in the Moon Theater, threatening Mike's life to get Buster to hand over the money in the chest. When Buster stalls, the bears smash the chest open with a baseball bat; and to their fury and the singers' shock, the contents were money and objects with a total monetary value of $1,000. Everyone's combined weight, along with the force of the baseball bat, caused Buster's makeshift glass stage full of water and squids to break, flooding the theater and causing it to collapse.
Thinking that Mike died in the flood, the bears quickly run before they can be connected with the theater's destruction.
Later, when the singers perform in the theater ruins, the bears see Mike singing "My Way" on TV and quickly head over to get their revenge. They manage to swipe Mike without being seen and the leader almost eats Mike again, only for Nancy to come to his rescue in Mike's car.
As they drive off, the two of them don't notice that the leader bear is still hanging onto the back of the car, sneering.