A struggling animator and the main character of the show. Voiced by Alice Ann Stacey.
- Adorkable: Despite her (justifiably) exasperated exterior, she's shown to be a comic book nerd and a LARPer and admits to being social awkward.
- Ambiguously Bi: Her ex's gender is intentionally unclear.
- Badass Adorable: An adorkable tomboy capable of kicking plenty of ass.
- Deadpan Snarker: When you work with people like Ben and Kate on a regular basis, this is necessary survival strategy.
- Hidden Depths: She's still somewhat bitter towards her ex for leaving her and she admits that Ben is her only friend.
- Masculine Girl, Feminine Boy: Masculine Girl to Ben's Feminine Boy.
- Only Sane Woman: Boy is she ever.
- Platonic Life-Partners: With Ben, whether she likes it or not.
- "The Reason You Suck" Speech: Delivers a (somewhat justified one) to Ben in "Firing Squad".
- Red Oni, Blue Oni: The deadpan Blue Oni to Bens eccentric Red Oni.
Self-proclaimed filmmaker and Lucy's best (and only) friend. Voiced by Tom Ridgewell.
- Adorkable: Sometimes, like when he dressed feminine or acts like a man child.
- Blue and Orange Morality: He seems to operate on this, hence his highly unethical filmmaking methods.
- Brother-Sister Team: With Kate.
- Catchphrase: "I'm a filmmaker!"
- Cloudcuckoolander: Big time.
- Establishing Character Moment: "Lucy, let's make a movie! Right! Hugging! NOW!"
- Mad Artist: He has his sister perform Satanic rituals to get actors for his films. And that's just for starters.
- Masculine Girl, Feminine Boy: Feminine Boy to Lucy's Masculine Girl.
- Only Friend: Lucy admits that he's hers.
- Platonic Life-Partners: With Lucy, whether she likes it or not.
- Red Oni, Blue Oni: The enthusiastic and goofy Red Oni to Lucy's no-nonsense levelheaded Blue Oni.
- Straight Gay: He's artsy and feminine, but this highlights his eccentricity rather than the fact that he's gay.
- Wholesome Crossdresser: As a kid, and also a couple of times in the intro.
Ben's demonic little sister who helps him with his movies. Voiced by Alice Ann Stacey.
- Affably Evil: She's perky and adorable, even if she's Satanic little monster.
- Ambiguously Human: She can float, is unkillable, has access to all sorts of demonic powers, and according to a photo of Ben and Lucy when they were kids, she doesn't age. Notably, she's stated to only be Ben's half-sister.
- Big Bad: Of the Eddsworld short "Trick or Threat", being the one possessing Edd and Matt into trying to kill each other for not giving her candy.
- Brother-Sister Team: With Ben.
- Cute and Psycho: She's a small, adorable girl who's also a Satanic occultist.
- Girlish Pigtails: Has them and they're cute.
- Enfant Terrible: A Satanic little girl.
- Iron Butt Monkey: Justified because she can't die.
- Nigh-Invulnerability: She can't die and has survived multiple injuries (being blown up, a plane crash, being beaten up by a giant gorilla, being attacked by a shark, being eaten by a giant bird, etc.) without so much as a single scratch.
- Power Floats: Her powers give her the ability to fly.
- Slapstick Knows No Gender: Being an unkillable demon child, Kate's the one member of the cast who's most likely to take a major beating in the show.
- Token Evil Teammate: The most outwardly malicious of the trio.
- Vague Age: She looks like a little girl and is referred to as a minor in the first episode, but is present in a childhood photograph of the ostensibly adult Ben and Lucy looking identical to how she looks now.