Lieutenant Kif Kroker (voiced by Maurice La Marche) is the long-suffering assistant to Captain Zapp Brannigan, and Fourth Lieutenant on the Democratic Order of Planets (DOOP) starship Nimbus.
Kif is a short and thin green-skinned alien crew member.
Dwight Conrad (voiced by Bumper Robinson in the TV series, Phil La Marr in the films) is the son of Hermes Conrad and La Barbara Conrad.
Morbo the Annihilator (voiced by Maurice La Marche) is the misanthropic alien anchor for Television Network.
Morbo is an advance scout for an upcoming alien invasion and does not bother to be subtle about it, often expressing his contempt and extreme hatred for mankind during live news broadcasts and commenting frequently on his species' extremely violent invasion plans. Scruffy (voiced by David Herman) is the Planet Express janitor and a recurring supporting character.
The first several times he is referred to or seen by his co-workers, they ask who he is, to which he replies, "I'm Scruffy.
The janitor." He is shown several times to read porn magazines like National Pornographic and Zero G Juggs (parodies of actual magazines, National Geographic and Juggs).
His frustration with Brannigan's arrogance and general incompetence in Season 1 leads him to be a disaffected, indifferent, sardonic lackey, although his personality differs greatly in later seasons.
Zapp thinks Kif to be his best friend and loyal confidant, whereas Kif sees Brannigan as an incompetent jerk, going so far as to call him a jackass in "Love's Labours Lost in Space".
He appears to be using his job to gather information about the human race to aid the planned invasion. His co-host Linda van Schoonhoven seems either blissfully ignorant or entirely dismissive of Morbo's hatred and usually responds with an empty-headed laugh to Morbo's contemptuous outbursts. Scruffy first appeared "Hell Is Other Robots" as a stagehand at a Beastie Boys concert, he was later added to the cast as a little-seen staffperson at Planet Express with the second-season episode "Anthology of Interest I".
Scruffy generally approaches both his job and the rest of his life with a high level of apparent apathy, as shown in "Parasites Lost", in which he ignores a broken boiler in the Planet Express Headquarters to read a pornographic magazine, and continues to read even after said boiler explodes, declaring, "Scruffy's gonna die the way he lived." In "Future Stock", it is revealed that he is deeply fond of the company, and owns four times as much stock as the other employees.
Cubert wants to do something 'better' with his life and does not accept the responsibility Hubert gives to him.
He believes that most things happen to be "Impossible" contrary to the Professor's belief that nothing is impossible.
Cubert has an epiphany after getting hit on the head, realizing how the starship engines Hubert invented work, allowing them to be repaired while Hubert is incapacitated.