Jack Haylee
- Voiced by: Robbie Rist
A young man from the city who inherits a farm from his great uncle. Once at the farm, he discovers it to be inhabited by monster animals. For the remainder of the series, he and the monster animals form a close bond and get into all sorts of misadventures.
- Smart People Wear Glasses: He wears glasses and is often shown to be intelligent. The episode "Home Office Horrors", for example, has him take a job designing computer software.
- Token Human: He is the only member of the main cast who is a human being as opposed to a monster animal.
Count Cluckula
- Voiced by: Bruce Mahler
A rooster vampire.
- Casanova Wannabe: He tries to hit on women, but he rarely wins their affections.
- Daywalking Vampire: He is never shown to suffer any ill effects from walking around in the sun.
- Half-Dressed Cartoon Animal: He wears a shirt, a coat and a cape, but no pants.
- Jerkass: Count Cluckula wants control over the farm which puts him at odds with Jack. He often delights in teasing and tormenting the other monsters, even when he definitely shouldn't.
- Token Evil Teammate: He is frequently shown to be the most self-centered of the monster animals.
Frankenswine
- Voiced by: Rodger Bumpass
A Frankenstein monster pig
- Big Fun: He's overweight, but a very nice person for the most part.
- Frankenstein's Monster: He's a porcine Frankenstein monster.
- Franken-X: He's a porcine Frankenstein monster named Frankenswine.
Goatasaurus Rex
- Voiced by: Rodger Bumpass
A giant goat dragon.
- Amazing Technicolor Wildlife: He's a purple-colored goat/dragon.
- Big Eater: Once Goatasaurus starts on one of his eating binges almost nothing can stop him.
- The Big Guy: The largest monster on the farm, any bigger and he'd be a Not Zilla.
- Breath Weapon: He can breathe fire, and if Goatasaurus gets the hiccups it threatens to burn down the whole farm.
- High-Class Glass: He occasionally puts on a monocle.
Dr. Woolly and Mr. Ewwe
Click here to see Mr. Ewwe
- Voiced by: Bruce Mahler
A meek, bespectacled sheep of great intellect who transforms into a vicious, deranged brute and back whenever he gets wet.
- Embarrassing Tattoo: "Fangs for the Memories" reveals that he has a risque tattoo somewhere on his body that can only be seen when he's been shorn.
- Jekyll & Hyde: Dr. Woolly is kindhearted and coy, while his alter ego Mr. Ewwe is a complete psycho.
- Shorter Means Smarter: He's both the shortest and the most intelligent of the monster animals.
- Smart People Wear Glasses: He wears glasses and is the smartest of the monster animals.
Zombeef
- Voiced by: Tifanie Christun
A zombie cow.
- Punny Name: Her name is a portmanteau of "zombie" and "beef".
- Raising the Steaks: She's a zombie cow.
- Tertiary Sexual Characteristics: The main signs that she's female are that she wears a bow, lipstick and a skirt.
- Two Girls to a Team: She and Cowapatra are the only two female monster animals in the group.
Cowapatra
- Voiced by: Kevin Killebrew
A mummy cow.
- Mummy: She's a mummy.
- Two Girls to a Team: She and Zombeef are the only two female monster animals in the group.
Pa
- Voiced by: Dan Woren
A balding farm magnate who schemes to buy the farm from Jack using any underhanded methods he can.
- Bald of Evil: He is balding and the show's main villain.
- Big Bad: Many of the show's conflicts are driven by his attempts to take the farm from Jack.
- Corrupt Corporate Executive: He's a captain of industry in farming who's trying to force Jack to sell him the monster farm.
Jimmy Earl
- Voiced by: Jess Harnell
Pa's son and assistant in his schemes to take the farm from Jack.
- The Dragon: He is his father's right-hand man and constantly seen helping him carry out his plans.
