With 50 years of men-in-masks, creepy monsters, and ghoulish ghosts, Scooby-Doo has quite a collection of scary villains in its arsenal.

Considering Scooby-Doo has been on our screens in various formats for over 50 years, a fair few monsters have shown their faces. Depending on which series you’re watching, some of these are the relatively unthreatening man-in-a-mask type deal, though the show is known to have dealt with some very real threats.

We’re counting down the top 10 scariest monsters ever to show up in the Scooby-Doo universe.

10 Phantom Virus

The Phantom Virus is taken from the 2001 film Scooby-Doo And The Cyber Chase and is one of the weirdest ‘real’ monsters the gang has ever dealt with. While his bright glow and low electronic buzz mean he isn’t exactly the sneaky type, the Phantom Virus' sheer power is something the gang found pretty difficult to contend with.

The Phantom Virus is also one of the deeper, more detailed monsters encountered by the gang, with the personality of its creator (an obsession with baseball) reflected in its coding.

9 Revolta

Scooby-Doo And The Ghoul School is a much more light-hearted effort. Much of the film's plot focusses on Shaggy, Scooby. and (unfortunately) Scrappy taking up positions as PE teachers in a school for the children of famous monsters.

All of the students are delightful, but behind the scenes, the creepy many-armed Revolta is cooking up a diabolical scheme. From her sinister echoing voice and her decaying flesh to the fact that she isn’t just someone in a mask, Revolta is as creepy as you can get.

8 The Ghost Clown

The Ghost Clown is the first entry on this list that isn’t a real-life monster come to haunt the Scooby gang. Taken from the original series of the show, Scooby-Doo, Where Are You!, The Ghost Clown is simply a disguise for Harry The Hypnotist. However, just look at him!

In the same world in which we can read about Pennywise, clowns have become one of the strongest, creepiest nightmare-fuels available. From the Ghost Clown's huge creepy smile and his demonic black and yellow eyes to the playful red bobble on the top of his hat, this guy was surely making people cower behind the sofa, even back in the '60s.

7 Mr. Hyde

Another of the Scooby-Doo writers' genius moves, Mr. Hyde is the ghostly disguise of, you guessed it, Dr. Jekyll. In order to cover up his jewel thefts, Jekyll dressed up as his green-tinted alternate self and terrorized the gang throughout the "Nowhere to Hyde" episode.

Hyde's sinister laugh coupled with the perceived power of his ability to scale walls made him a hard one for the gang to get a hold of, but in the end, they were able to unmask him.

6 The Tar Monster

The Tar Monster does pretty much exactly what it says on the tin. It’s a monster, made of tar. You might recognize him from his re-appearance in Scooby-Doo And The Cyber Chase, where he was reanimated by The Phantom Virus along with a whole host of past villains, but his first appearance came in The Scooby-Doo Show.

The Tar Monster's lumbering movement and inability to speak made him a horrifying thing to encounter, and his unique ability to wade through tar (and, obviously, be made from it) made him an interesting one. However, it turned out to simply be a professor’s assistant using a scuba-diving suit to swim through the tar.

5 Mirror Monster

The Mirror Monster is another character from The Ghoul School. Considering this particular film focuses mostly on making its monstrous main characters appear quite lovely, the final act introduces some truly terrifying beasts. The Mirror Monster, in particular, is a snarling mirror image of Shaggy, who replaces his good-natured fear with a horrifying desire to scare.

Seeing Shaggy with spiraling red and yellow eyes, pointy ears, ruffled hair, and sharp teeth is an image ready to scare anyone expecting to see the kindly yet terrified face of Shaggy Rogers.

4 Redbeard’s Ghost

The Ghost Of Redbeard is no stranger to the Scooby-Doo franchise, appearing first in the Scooby-Doo, Where Are You!'s "Go Away Ghost Ship" episode. Later on, Redbeard turned up in the Harlem Globetrotter’s crossover episode and the ghost even made a cameo appearance during 2014’s Scooby-Doo! Frankencreepy.

Despite being the evil CL Magnus in disguise, Redbeard was still a fierce and scary presence. He captured prisoners, threatened death (which was quite rare for Scooby-Doo), and forced his subjects to cook.

3 Werecats

Arguably the scariest Scooby-Doo film ever made, Scooby-Doo On Zombie Island, is built around the terrifying actions of the Werecats. The trio of hairy beasts are able to remain immortal by draining the lives of others during the harvest moon.

Pretty terrifying, considering these aren’t the classic masked-villain type. They’re all too real. Equipped with a horrifying amount of strength, razor-sharp claws, and voodoo dolls that can be used to control the movements of the gang, these guys were the ultimate overpowered enemy.

2 Zombies

Taken from the exact same film as the Werecats, the graphically detailed zombies weren’t so much of a threat to the gang, but they did serve as a warning. This meant they’re one of the more unexpected, twist-heavy monsters in Scooby-Doo history, but didn’t stop them being scary before we found out their true intentions.

The zombies have detailed, deathly features and omitted bone-chilling tortured growls. The moment that a skeptical Daphne realizes there are 100% real dead people standing before her remains goosebump-inducing to this day. Considering this is primarily a kids' show, the idea that reanimated corpses were wandering the island for the duration of the film is a creepy thought.

1 Ben Ravencroft

The reason Ben Ravencroft made it to the top of our list is because of his remarkable ability to convince everyone that he was kind, well-intentioned, and lovely. The writer (voiced by the incredible Tim Curry) caught the affections of the whole gang, especially Velma, but he turned out to be a manipulative ancestor of a powerful witch who was imprisoned in a book for centuries.

Via his ancestor, Ben unlocks terrifying Warlock powers that made him one of the most powerful (and real) monsters the gang ever encountered. In the end, Ben's attempt to betray his own relative proved futile, as she was able to overpower and imprison him herself.

NEXT: Scooby-Doo: 5 Things The Live-Action Movies Got Right (& 5 Things It Got Wrong)

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