Ultra Magnus generally appeared as a chief lieutenant to the leader of what fictional group of sentient robots?
Optimus Prime Optimus Prime is a fictional character from the "Transformers" franchise. He is the leader of the Autobots. A fictional group of sentient robots that can transform into other forms (e.g: cars and other objects) He is the most iconic of the Transformers, being frequently featured in Popular Culture.
Kroton (Cyberman) Kroton is a fictional character who appeared in the "Doctor Who Magazine" comic strip based on the long-running British science fiction television series "Doctor Who". He was a companion of the Eighth Doctor. He should not be confused with the Krotons, the villains of the 1968 serial "The Krotons".