Cappy is a young robot, living and working in Robot City as Bigweld Industries' only female co-executive. Unlike Ratchet and his sycophants, she sympathizes with the outmodes as their parts are cut off to make way for Ratchet's new plan. Upon meeting Rodney, she quickly begins to develop a crush on him and wants to keep him and Bigweld out of trouble, especially from Ratchet. She becomes Rodney's ally and companion, serving to help him and his friends when they are in danger.
Cappy is a calm, but also strong-willed and clever co-executive at Bigweld Industries. Although she is not nearly as outgoing and vigorous as Piper, she is also not willing to conform to Ratchet's agenda and cannot be intimidated by him like her other co-workers. She is one of the more level-headed and reasonable characters in the movie, and sympathizes with the robots who have been "outmoded" because of the changes Ratchet made to Bigweld Industries. Despite this, Cappy still does nothing to attempt to find Bigweld or solve the mystery of his disappearance. Rather, she passively pretends not to mind the changes Ratchet makes. However, she also does not respond to his constant flirting, and chooses to ignore it. She dislikes Ratchet because of his arrogance and uncaring attitude toward other robots.
When she first meets Rodney, she takes an instant liking to him because of his enthusiasm for being an inventor and his wish to meet Bigweld. When their paths cross again at the Bigweld Ball, she is once again shown to admire him when he speaks up and loudly questions Ratchet on where Bigweld is. However, this time she tries to protect him from Ratchet's wrath, even going as far as pretending to flirt with Ratchet so she can help Rodney escape. She also helps Rodney get to Bigweld's mansion, where the two meet him in person. After this experience, Cappy faithfully assists Rodney for the rest of the movie and openly opposes Ratchet in order to stick with him. At the victory celebration in Rivet Town, the two are shown dancing with each other and then embrace warmly. It can be assumed that they are now boyfriend and girlfriend.