Moby is a orange robot that helps Tim, his best friend, with the BrainPOP episodes. He does not speak like a normal human, instead makes "beep" sounds, which Tim apparently can interpret. His full name is Moby von Robot the Third.
He is President and apparently Founder of FNBM, or First National Bank of Moby. However, it soon apparently failed, as Moby admitted that he didn't know the difference between simple and compound interest. It also appeared in another episode, in which Moby entices Tim into joining his bank again.
He often refers to world conquest as a personal wish, and claims that someday robots will conquer the world. He appears to be an experimental NASA robot due to the fact that he has rocket on his feet and a teleporter built in to his right hand.
He is on the FBI's Most Wanted List along with Tim for sinking a US Navy Carrier Strike Group while helping Tim answer a letter about warships. (The video was terminated due to disturbing content).
He apparently doesn't want to answer questions about his ancestry, as it was shown in Writing Process, Geologic Time and Outer Solar System when he hypnotized Tim for asking questions about his origin. In Geologic Time, Moby shocks Tim instead.
It was hinted that he was built by Leonardo da Vinci in one episode, although this seems more like a joke, as Tim says "Oh no way!".
In the episode Biography, an autobiography written by Moby has his name as 'Moby Calrissian'. This may be a reference to the Star Wars character Lando Calrissian