In the 2017 film Transformers: The Last Knight, the character known as the Butler is actually named Cogman. He is a small, human-sized Cybertronian who serves as the loyal manservant, bodyguard, and chauffeur to the eccentric English historian Sir Edmund Burton. Described in the film's production as a Headmaster, a type of Cybertronian who can detach to form the head of a larger robot, Cogman is designed with a unique aesthetic that reflects his long history. His body is crafted to look like a highly detailed, turn-of-the-century automaton, appearing as if made from the fine gears, silvery metal, copper, and brass pieces of an expensive French watch.

Cogman's personality is a stark contrast of refined service and barely concealed violence. He has served the Burton family for centuries, likely over seven hundred years, and outwardly presents himself as the perfect butler: polite, proper, respectful of tradition, and capable of a dry, witty quip. However, this facade masks a deeply unstable and psychopathic nature. The film’s writers described him as a psychotic robot who constantly wants to kill people, and his behavior is marked by an extreme and comical streak of anger management issues. He is often cranky and rude, and his primary motivation appears to be a fierce, if volatile, dedication to his duty and to Sir Edmund, whom he respects as the greatest Witwiccan he has ever served. Despite his homicidal impulses, he remains fundamentally loyal to his master and his centuries-long mission to protect the family's secrets and artifacts.

In the story, Cogman serves as the initial contact for the protagonist Cade Yeager. He is sent by Sir Edmund to retrieve Cade and bring him to England, introducing the human characters to the hidden history of the Transformers on Earth. Beyond his role as a butler, he acts as a capable getaway driver and a surprisingly effective fighter, engaging in action sequences that led to him being described by a producer as a "ninja". His key relationship is, of course, with Sir Edmund Burton, acting as his constant companion and protector. He also has notable interactions with Cade Yeager and the Oxford professor Viviane Wembly, whom he serves with the same blend of formal courtesy and underlying menace. Cogman does not undergo significant character development, remaining a consistent source of erratic and violent comic relief throughout the film.

Cogman's most notable abilities are his extreme durability, superhuman strength for his size, and proficiency in hand-to-hand combat, which he uses to assault much larger opponents without hesitation. His small stature allows him to be highly agile and mobile, and he integrates his combat skills with his function as a chauffeur, often engaging in high-speed pursuits and fights while driving. He is also incredibly long-lived, having been active and serving the same human family for centuries without any significant change to his form or core programming.