Cubert J. Farnsworth is a clone of Professor Hubert J. Farnsworth, and is often referred to as his son.
He is heir to Planet Express and the Professor's fortune, being, along with the Professor's parents, one of the Professor's closest living relatives. He spends most of his time with the Planet Express crew criticising everything and routinely pointing out logical fallacies.
At first Cubert did not want to follow in his father's footsteps and become a scientist, thinking that scientists were useless. However he eventually changed his mind and said he wanted to be just like Hubert. Though he is a clone, Cubert and Hubert act as though they are father and son. Cubert's best friend is Dwight Conrad.
Cubert is regarded as uncool and unpopular among other children and is often picked on by Brett Blob. At one point, he and Dwight attacked Brett with salt which affected the slimy alien in a similar way it affects a slug, though Brett was able to recover from it before long. Cubert is also often nasty and derisive to the other members of Planet Express, frequently pointing out their flaws in a nasty manner or insulting them just for the sake of it.
Cubert often likes to snort like a pig to emphasize when he's being sarcastic or to point out the obvious.