Angela was originally an employee of MegaCorp, who then turned against it after it started manufacturing uncontrolled ProtoPets. She attempted to steal the ProtoPet but was thwarted by Ratchet & Clank. When she eventually convinced them of the plot to use the ProtoPets to conquer the galaxy, she teamed up with them and ultimately stopped the project.
While Angela was originally thought by many to be a Lombax, it is explained in Tools of Destruction that Ratchet is the only Lombax in existence, which means that Angela, assuming she is still alive, presumably is not a Lombax. She is, it should perhaps be noted, different to Ratchet in various ways including being much taller and having no tail.
