Audiences remember The Creeper, The Spooky Space Kook, and terrifying villains like El Chupacabra in the Scooby-Doo franchise. However, some villains the gang ran across over the years were truly silly and laughable, for several reasons. The aliens in Scooby-Doo and the Alien Invaders were much too campy and inept to be taken seriously, and Marcy in What's New Scooby-Doo decided that property damage would be the best way for her birthday to be remembered.
From their silly schemes to their ridiculous actions and cheesy (one monster was literally made of cheese!) costumes, there are some villains that were just too foolish to be taken seriously.
Marcy (What's New Scooby-Doo?)
Marcy ranks among the silly villains because of the motivation behind her nefarious acts in the Halloween episode of What's New Scooby-Doo? as well as thinking that her plan would truly get her what she wanted. She is angry because her birthday is overlooked, due to the fact that it's on Halloween.
Of course, it's understandable that she'd be hurt that her parents forgot her birthday and that Halloween takes precedence year after year, but creating an army of scarecrows, destroying corn fields and people's livelihoods, and scaring people is definitely excessive to make her point. It's a lot of trouble to go to simply to remind people that it's her birthday. Ultimately, it's ridiculous that she thought anyone would think of her forgotten birthday instead of her destroying their corn fields.
The No-Faced Zombie (The Scooby-Doo Show)
The no-faced zombie limps when he walks, but he's still able to limp and run, which looks rather ridiculous onscreen. He's later discovered to be a robot, which makes that possible, but it doesn't lessen the absurdity of it.
He also doesn't seem to be well-programmed, given he keeps losing the valuable coin he stole to the gang, and has trouble locating his programmer. Essentially, neither the zombie nor his programmer are the most intelligent villains, given the ridiculous zombie portrayal and the lack of a backup plan, which they definitely needed to give the complications that arose.
Lady Vampire Of The Bay (The Scooby-Doo And Scrappy-Doo Show)
The Lady Vampire bears a certain resemblance to Daphne, which is one of the things that makes her so silly, as it lends to Shaggy's, Scrappy's, and Scooby's belief that Daphne herself is the vampire.
Plus, the Lady Vampire isn't very scary, from her typical hissing when she speaks to her campy "stay out of my business or else" threats. She's not very scary or memorable. The episode itself, because of the villain, is more corny and hilarious than anything else.
The Phantom Virus (Scooby-Doo And The Cyber Chase)
The main villain in Scooby-Doo and the Cyber Chase is hard to take seriously, if only for his multiple baseball puns. His powers are dangerous, but he never seems to use them to their full extent, at least not significantly enough until the gang reaches the final level of the game.
Still, throughout the game, the Phantom Virus relied heavily on various henchmen and his veiled threats organized as baseball puns to scare the gang, which in itself is pretty silly. He's not to be taken too seriously, and early on, the gang knew that his version of kryptonite was magnets, thus diminishing the overall threat knowing that there was a way to defend themselves.
The Scooby Snack Monster (What's New Scooby-Doo?)
Now, a Scooby Doo villain made up of the snack that Scooby and Shaggy love the most is pretty silly. Audiences would think that the two would be thrilled to finally come up against a tasty monster. Granted, the glowing yellow eyes are freaky, and the monster could sometimes go to extreme lengths (like the time it trapped Shaggy and Scooby in a tube, and they were nearly sliced by a fan), but overall, Shaggy and Scooby didn't seem as scared of the villain as they usually are.
Shaggy and Scooby even happily eat the trail the monster leaves behind. It's silly that the two didn't think to just eat the monster like they had eaten its footprints, and even sillier that a monster like this should be scary to them.
The Cheese Monster (A Pup Named Scooby-Doo)
The Cheese Monster was out to put the Scooby Snack factory out of business, but the monster should've been out of business long before his expiration date. Food is what Shaggy and Scooby love the most; perhaps they were terrified of their favorite thing chasing them initially, but still, they should have thought to eat the monster much sooner.
Scooby eventually did to save his captured friends, and they found him happily full and proud of himself for this feat. The costume was silly and not very practical in itself to rely on cheese for a fear factor, which the villain underneath found out the hard way.
Max, Steve And Laura's Alien Trio (Scooby-Doo And The Alien Invaders)
The alien costumes are the first silly thing to note. They're not original, with green skin, red eyes, otherworldly-looking gear, and of course, the alien anatomy of their heads and hands. Steve, Max, and Laura really stuck to the campy book on everything alien, from kidnapping people in a spaceship to their costumes to their mannerisms.
Their silliness comes to a head when they are faced with real aliens Crystal and Amber, who are nothing like their fake counterparts, and who definitely upstage and make the other aliens look foolish. This was probably the whole point of the film, but it doesn't undermine the comedic factor of the campiness of the humans masquerading as aliens.
The Werewolf (Scooby-Doo Where Are You!)
The werewolf isn't the brightest of villains. He falls down a trap door that Shaggy and Scooby inadvertently open when he should've known it was there given the mill is his place of haunting. He also followed them for some time and managed to miss several opportunities to surprise the duo as well, which didn't look good for him.
What's more, he allowed himself to be tricked into being given a haircut by Shaggy and Scooby later in the episode, sticking around long enough for them to render him bald. Then, he gets caught in a waterfall and cries for help. His actions are what make him so silly, and by extension, more laughable than frightening. It's granted he was a better sheep smuggler than a ghost any day, and couldn't multitask.
The Housekeeping Couple (The New Scooby-Doo Movies)
The elderly housekeeping couple initially worked in the Addams house, and they are definitely among the silliest villains the gang has ever come across. Their whole reason for orchestrating their scheme, involving their mechanical vulture, was because they wanted the Addams family to move, fearing their presence had a bad effect on the neighborhood children, as they saw it.
Even Velma was somewhat exasperated when she learned their motivation. The couple's efforts to scare the Addams family were weak, considering no one in the family was frightened. Furthermore, having been in their house, the couple should know that anything spooky would be met with eagerness, not fear, in the Addams household. They also risked some form of kidnapping by making Wednesday Addams disappear. All in all, their entire scheme was ridiculous. While the vulture was a convincing villain, the couple behind it was simply imprudent and laughable.
Asa Shanks (Scooby-Doo Where Are You!)
The headless specter has got more going for him than Asa Shanks. Ultimately, Asa is the real villain in "Haunted House Hang-Up" as he was after the Stillwall treasure, but his disguise and his backup plan should anyone catch him in the act were truly laughable.
His disguise is a simple sheet, and he's still wearing the same clothes he was when he met the gang on the road, already clueing audiences into his identity. He proceeds to chase Fred and Shaggy with a weak "rawr" kind of sound, before being tripped and slamming headfirst into a column, ending his shenanigans. From his costume to his capture, Asa Shanks was an entirely silly villain.