Cal, whose full name is Colin Banes, is a supporting human character in the live-action Transformers film continuity. He is primarily known as the father of Mikaela Banes, a main protagonist in the first two films.

Cal has a deep and long-standing background as an automobile mechanic, possessing an expert-level knowledge of cars. In the past, however, he used these skills for illegal purposes, having been a car thief for an extended period. During his life of crime, he would sometimes bring his young daughter, Mikaela, along on his heists, inadvertently teaching her the skills of the trade. This lifestyle eventually led to his arrest and incarceration after he and Mikaela were caught by the police.

By the events of Transformers: Revenge of the Fallen, Cal has been released from prison and is making an effort to lead a more stable life. He has secured legitimate employment at a motorcycle repair shop called Mike's Custom Cycles, where his daughter also works.

Cal is characterized as being something of a "man-child," suggesting a personality that is somewhat immature and reliant on others for guidance and stability. His entire identity is deeply wrapped up in his profession; his love for repairing and understanding vehicles is so profound that he once claimed he would not want to go to heaven if there were no cars there for him to fix.

A major part of Cal's motivation in the story is the need to maintain his newfound stability and avoid slipping back into his old criminal habits. His daughter, Mikaela, is acutely aware of this vulnerability. This is the primary reason she chooses not to follow her boyfriend, Sam Witwicky, to college on the East Coast. Her stated motivation is to remain home to provide a stabilizing influence on her father, ensuring he does not relapse into his past behavior.

Cal's role in the plot of Revenge of the Fallen is indirect but thematically significant. He does not participate in the central action involving the Autobots and Decepticons. Instead, his presence serves as a key narrative device to explain Mikaela's absence from the main character's early college life and to ground her character in a sense of family responsibility. His personal struggles provide the backdrop for her decisions and her maturity.

His most important relationship is, of course, with his daughter, Mikaela. Their bond is complex, born from a past where he exposed her to crime but also taught her valuable mechanical skills. By this film, their dynamic has shifted, with Mikaela taking on a more responsible, almost parental role in their relationship to ensure her father's success in staying out of trouble.

Over the course of the story, Cal does not undergo a significant personal development arc. His primary journey is an off-screen one, transitioning from a life of crime to an honest job. By the time of the film, he is in a state of maintenance, with his daughter working to prevent his backsliding. He has no notable abilities related to combat or the central conflict of the film. His sole expertise is mechanical, specifically related to automobiles and motorcycles, a skill he has used both legally and illegally.