Whether it's intentional or not, some monster movies are known for their horrendous application of computer-generated imagery. It's always disappointing when a big-budget monster movie reaches its big reveal, only to showcase a CGI creature that looks really, really bad. Thanks to pixelation, incorrect dimensions, and a lack of any realism, these fiends come across as more ridiculous than scary.
Believability isn't always the most important quality fans seek out in monster movies, though. In fact, fans out of low-budget horror look forward to catching glimpses of a movie's monster on-screen — anticipating just how terrible and kitschy it will be.
Anaconda 3: Offspring (2008)
There are five, count 'em, five feature films in the Anaconda franchise. The 1997 debut starring Jennifer Lopez and Ice Cub set the standard for amateurish CGI giant snakes, and it only gets worse with each sequel.
Anaconda 3: Offspring is a made-for-TV SyFy venture starring David Hasselhoff as a mad scientist who breeds the titular beasts for cancer research. The "so bad it's good" film is composed of one outrageous slithering software snake after another.
Mega Piranha (2010)
Imagine a world wherein a rare species of oversized piranha makes its way to Florida at the height of tourist season. This is exactly how events go down in Mega Piranha, and the fishy behemoths in question typify awful computerized special effects.
These distorted, toothy monstrosities consume submarines, battleships, and helicopters as they travel north from Venezuela. Warped and grainy, the mega piranha jump around and feast upon everything in sight.
Boogeyman (2005)
According to the 2005 film Boogeyman, the creepy entity in the closet is just a blotchy green guy with really bad teeth. Even though it did well in theatres, the big monster unveiling in this horror film is one of the most unsatisfying of all time.
As it goes with the CGI Boogeyman, the rest of the movie is a washed-up, second-rate mess. Fans of bad editing and sloppy digitals won't regret a few viewings of this blunderous feature.
I Am Legend (2007)
I Am Legend director Francis Lawrence originally cast actors wearing prosthetics to play the vampirish, infected Darkseekers. Lawrence felt the practical effects weren't believable enough, so he decided to increase his budget by using CGI for the monsters.
The result, some critics believe, is much worse than any prosthetics could be. Ultimately, this Will Smith movie adapted from the classic horror novel by Richard Matheson had the pundits divided.
Freddy Vs. Jason (2003)
In the already suspect cross-over movie Freddy vs. Jason, lousy CGI effects reach a new low. In the film, Jason Voorhees and Freedy Kreuger battle it out, bringing a group of teens into the middle of their carnage.
Freddy vs. Jason hits rock bottom when Freddy makes his move on a stoned high schooler named Bill. Freddy appears as a poorly-rendered, hookah-smoking caterpillar that eventually crawls into Bill's mouth and takes control.
3-Headed Shark Attack (2015)
The saying goes that three heads are better than one, but whoever is responsible for that quote never anticipated a three-headed CGI shark as the centerpiece of a trashy horror movie. The film's mutated great white hangs out around the giant garbage patch in the Pacific Ocean, where it devours everyone from partying teenagers to researchers.
3-Headed Shark Attack is the sequel to 2012's 2-Headed Shark Attack, and it delivers even more insanity than its predecessor. For those who crave an oceanic killing machine with even more heads, 3-Headed Shark Attack is followed by a fourth, fifth, sixth, and seventh installment.
Let The Right One In (2008)
Let The Right One In is a shocking and emotionally evocative horror film about a bullied Swedish boy who becomes friends with a young female vampire. It tops quite a few of the "Best Horror Movies" lists, yet it contains one major flaw from a special effects perspective.
In the middle of the film, a woman on the eve of becoming a vampire is attacked by a pack of triggered cats. These computer-generated felines look much more like digitized taxidermy than the real thing.
Deep Blue Sea (1999)
Deep Blue Sea employs both practical and CGI effects for its genetically modified sharks, leading to a mixed bag when it comes to visual appeal. One of the worst instances of lackluster cinematic CGI arrives when Samuel L. Jackson's character Russell is devoured by a cartoonish mako.
The finned predator literally jumps out of the water and grabs Russell as he gives a monologue about the importance of everyone working together as a team. What could have been a concrete jump scare becomes a laughably bad moment thanks to the shark's silly appearance.
Ice Spiders (2007)
Only SyFy could be responsible for a low-budget movie like Ice Spiders. Set in skier's paradise Utah, the film centers around a group of vacationers who are besieged by a legion of freakishly large spiders. It turns out that a research center up the road from the ski resort has been conducting bizarre experiments on spiders, and now they've broken loose.
The CGI spiders in the movie are green, two-dimensional baddies superimposed over the film's snowy landscape. Talk about sticking out like a sore thumb.
Birdemic: Shock And Terror (2010)
Birdemic: Shock and Terror pays homage to Alfred Hitchcock's The Birds, but its computer-generated, winged wildlife is about as bad as it gets. This James Nguyen film is infamous for its poorly rendered CGI — including eagles, vultures, and sprite that spit acid from their beaks.
There's also a love story buried deep below all the visual lunacy. Nguyen followed suit with Birdemic 2: The Resurrection in 2013.