Scorch's younger brother and the head of mission control at BASA. After quitting (in which Scorch says he's fired), he decides to rescue Scorch himself.
- Badass Boast: "In a galaxy filled with nerds, I'm their king."
- Big Brother Instinct: Despite all the crap he had to put up with Scorch, Gary will do anything for his little brother's safety.
- Butt-Monkey: He is always clumsy and gets a lot of injuries.
- Heel Realization: During the film's darkest hour, he apologizes for his past behavior.
- The Hero: Of the movie. After Scorch gets himself captured, it is up to Gary to rescue his younger brother.
- Nice Guy: A lot more humble and sensitive than his brother.
Gary's older brother, an arrogant but benevolent space pilot.
- Big Little Brother: He's is tall and broad, and his "little brother" Gary, who is shorter, skinnier and, as he keeps pointing out, older despite that.
- Catchphrase: "Scorch me, baby!"
- Chick Magnet: A line from Gabby indicates that a number of women are attracted to Scorch.
- Cool Uncle: To his nephew, Kip. He dedicated Earth to him.
- Decoy Protagonist: He is the first character to appear in the movie. The real protagonist is Gary.
- Dumb Muscle: Scorch may have the strength, agility, and courage, but he lacks the focus and rationality.
- Friend to All Children: His scene with Baab babies and relationship with Kip solidifies him as one.
- The Lancer: Acts as a foil to Gary.
- Living Legend: Given the statue of gold built in his honor.
BASA's no-nonsense chief.
- Bitch in Sheep's Clothing: At first, she is the sassy chief of BASA. Now she is the true Dragon to Shanker.
- The Dragon: To Shanker.
- Interspecies Romance: Thinks she has one with Shanker, but is really just his Unwitting Pawn.
- Red Is Heroic: Lena wears a red dress and wants to find the captured Scorch. Subverted, she turns out to be working for Shanker.
- Ungrateful Bitch: When Kira tries to comfort Lena and reassure her she can still do the right thing after the latter comes to realize Shanker was using her, Lena instead tries to kill Kira while mocking her for being naive.
- What Happened to the Mouse?: She is nowhere to be seen after she gets beaten by Kira.
The villainous head of Area 51.
- Alliterative Name
- Bald of Evil: Which he covers with a wig when he talks with Lena.
- Big Bad
- Disproportionate Retribution: He wants to wipe out all aliens because the grays accidentally crashed their flying saucer on his father.
- Fantastic Racism: He despises all aliens.
- Final Solution: He views aliens with so much hatred and contempt that he is willing to destroy every single star in the sky; countless untold and possibly innocent civilizations, just because his father was accidentally flattened by a crash-landing UFO.
- Freudian Excuse: See Disproportionate Retribution above.
- Manipulative Bastard: He feigns romantic interest in Lena so she will send him Scorch (unwittingly carrying the flubonium Shanker needs for his weapon).
- Strong Family Resemblance: To his father.
A mouse-like alien who Gary befriends and weds Scorch and Gabby at their wedding. He hosted a radio show on his planet that got so famous that he invented the social networking service.
- Big, Thin, Short Trio: The Short to Io's Big and Thurman's Thin.
- Deadpan Snarker: The most sarcastic in the movie, second only to Gary.
- Hates Being Touched: He reacts badly when Scorch strokes him like a pet.
- Meaningful Name: Doc is a radio talk show therapist.
- Miles Gloriosus: He likes to act like he's brave and unshakeable, but often runs and hides when trouble comes.
- The Napoleon
- Pintsized Powerhouse: He is small, but uses his Big Guy powers.
A 3-eyed slug-like alien with 4 arms who Gary befriends and becomes his cellmate at Area 51. He was a professor on his planet where he had invented touchscreen technology.
A giant cyclops-like alien with anger management issues who Gary befriends. She worked as a librarian on her planet until she got so mad at looking up stuff for her kind that she invented the web search engine.
- Berserk Button: Quite sensitive about her eye.
- Big, Thin, Short Trio: The Big to Thurman's Thin and Doc's Short.
- The Big Guy: She is the biggest of the main characters.
- The Chick: She plays this role in the movie.
- Cyclops: One single eye.
- Fiery Redhead: Io is a big, red-scaled alien with anger issues.
- Vocal Dissonance: Despite her enormous size, she has a pretty normal voice.
Gary's wife and Kip's mother.
- Action Mom: Kira has not lost her edge after becoming a mother.
- Nice Girl: The least snarky one in the cast and commentary states she wants to fix the pain that's happened in her family
- Retired Badass: Kira retired from BASA so she could focus on being a mother. But, don't underestimate her.
- Tiny Guy, Huge Girl: The Huge Girl to Kip's Tiny Guy.
Gary and Kira's adventurous son and Scorch's nephew.
- Badass Adorable: Proves this when he manages to control the plane carrying the rest of the heroes from mission control.
- Big Damn Heroes: He has two: He saves Kira from Lena's guards and at the final battle, he swoops in to help Scorch, Gary, and his new friends defeat the jets.
- In-Series Nickname: Sometimes called "Kipper" by his parents and uncle.
- Keet: Always bursting around with energy.
- Tagalong Kid: The youngest main character, but isn't a nuisance.
- Tiny Guy, Huge Girl: The Tiny Guy to Kira's Huge Girl.
- Advertised Extra: Her actor's name is on the poster, but she only shows up the beginning and the end of the movie.
- Clingy Jealous Girl: She tells other females interested in Scorch to stay away from him, on live TV.
- Satellite Love Interest: We only know that she's a reporter and Scorch's girlfriend and later wife.