The pixel art images used for the main characters are used in the cast page for the comic, and were created by the comic's artist, Tim Weeks.
Kade (male, Dog / Blue Merle Australian Shepherd)
- Annoying Younger Sibling: Although only three minutes younger than Nicole, tends to be rather annoying at times.
- Attention Deficit... Ooh, Shiny!: Has a tendency to be distracted.
- Hidden Depths: Although greatly obsessed with video games, he is said by Tim to be a programmer who works from home.
- Freakiness Shame: Kade has an amber right eye, which he wears a colored contact lens in because he was teased about his eyes as a puppy.
Nicole (female, Dog / Red Merle Australian Shepherd)
- Ambiguous Gender: Even though she has Non-Mammalian Mammaries and other Tertiary Sexual Characteristics, and despite not having a Gender-Blender Name, some fans (especially early on) didn't realize Nicole was female. Harvey once lampshaded this.
- Hot-Blooded: Has a tendency for violence, and is short-tempered.
- Not So Above It All: She fancies herself the more mature sibling, but she's not above immature things (wearing collars has been noted by Tim as an immature trait in this story), and it's unknown if she even has a job.
Rick (male, Iguana)
- Hidden Depths: It's mentioned Rick has his own apartment, so it's likely he has a job.
- God Like Gamer: He demonstrates this trope in the strip about Until Dawn, as he wastes his time trying to figure out every possible outcome.
- Fully-Dressed Cartoon Animal: Always more fully-dressed than the mammalian characters since he's cold-blooded, and scaled instead of furry.
- Shown Their Work: Due to being a reptile, Rick is cold-blooded. On two occasions so far, he has ended up falling asleep because he got too cold.Nicole: Welcome back to the land of the living.
- Technicolor Eyes: Rick has golden eyes, and a slightly lighter golden color for his sclerae.
Riley (female, Dog / Long-Haired Dachshund)
- Half-Dressed Cartoon Animal: As is true with most mammalian female characters (except Nicole), Riley wears a shirt. She also usually wears a flannel jacket.
- Otaku: Heavily invested in Japanese culture.
- Straight Man: She's far more frequently squicked by the paranormal activities at Kade and Nicole's place than Rick is.
Harvey (unknown gender, Ghost-possessed skull)
- Ambiguous Gender: Its gender is unknown, and Harvey has no knowledge of its life before becoming a spirit.
- Demonic Possession: Is a spirit possessing a skull of an unknown species. Various characters describe it as rabbit-like.
- Ineffectual Sympathetic Villain: He has some rather bad desires, but he's almost completely ineffective at being scary. The only one of the main cast he can actually scare is Riley, and even that is starting to decay.
- The Napoleon: Harvey fancies itself an "elder god", a reaper of souls, and potential destroyer of worlds. There's little evidence it has much supernatural power of its own beyond being able to grasp things, and maybe make thermite.
- Nice Job Breaking It, Hero: After Uncle Scooby's death, Harvey scared his probate attorney while he was examining the jar containing Ness's soul, causing him to drop and break it.
- Pyromaniac: Has an obsession with thermite.
- Reality Subtext: After establishing itself as a member of the household, Harvey starts moonlighting as a video game streamer with the screen name Harviplier.
- Red Eyes, Take Warning: When it's up to no good, or otherwise angry, its eyes glow red.
- Speak of the Devil: Speaking its name three times might summon it, it's possible Harvey was messing with them.
- The Thing That Would Not Leave: Is this to the twins. He was also this to Uncle Scooby, though he stayed hidden from them when they visited in their younger days. He didn't become their "friend" until after they inherited the mansion.
- Weaksauce Weakness: Light from an NES Zapper gun, and holy water, are both weaknesses for Harvey.
Ness (unknown gender, Ghost-possessed dragon plush)
- Ambiguous Gender: Although its actual gender is also unknown, Ness is frequently referred to as female since that's how Nicole referred to the dragon plush it now possesses.
- Cuteness Proximity: Kade, Rick, and Kade and Nicole's mother all find Ness adorable.
- Demonic Possession: Before possessing Ness, it possessed Kade's ROB robot, and later briefly possessed Nicole.
- Dragon Hoard: It adopted this trait of her plush possession when the group was done playing Sea of Thieves.
- Red Eyes, Take Warning: Same thing as Harvey, but its eyes normally glow green when not angry.
Uncle Scooby (male, Great Dane (deceased))
A friend of one of Kade and Nicole's grandfathers, he died under mysterious circumstances early in the comic's history, leaving his haunted mansion to the twins.- Cool Uncle: Although not by relation, he was a beloved elderly figure for the twins.
- Honorary Uncle: He was a friend of Kade and Nicole's grandfather, but wasn't a blood relative.
- Memetic Badass: According to Dad, stories of Scooby fighting ghosts were just that. But his hidden history with Harvey might say otherwise.
- Posthumous Character: He only appears alive in the flashback segment of the print collection's bonus story. (Public February 2024.)
- Shout-Out: Scooby is clearly based on Scooby-Doo, and his death in-story occurred not long after the death of the original voice actor for Shaggy, Casey Kasem. He has the same kind of collar charm as the original, and a mug with the same color scheme as Mystery Inc.'s van, the Mystery Machine.