Slither (2006)

Four interwoven stories that occur on Halloween: An everyday high school principal has a secret life as a serial killer; a college virgin might have just met the one guy for her; a group of teenagers pull a mean prank; a woman who loathes the night has to contend with her holiday-obsessed husband and a mean old man meets his match with a demonic, supernatural trick -or treater.

Trapped in an isolated gas station by a voracious Splinter parasite that transforms its still living victims into deadly hosts, a young couple and an escaped convict must find a way to work together to survive this primal terror.

Patrons locked inside of a bar are forced to fight monsters.

After his wife falls under the influence of a drug dealer, an everyday guy transforms himself into Crimson Bolt, a superhero with the best intentions, but lacking in heroic skills.

About the inhabitants of a small Iowa town suddenly plagued by insanity and then death after a mysterious toxin contaminates their water supply.

A nurse, a policeman, a young married couple, a salesman, and other survivors of a worldwide plague that is producing aggressive, flesh-eating zombies, take refuge in a mega Midwestern shopping mall.

A caving expedition goes horribly wrong, as the explorers become trapped and ultimately pursued by a strange breed of predators.

A young man's mother is bitten by a Sumatran rat-monkey. She gets sick and dies, at which time she comes back to life, killing and eating dogs, nurses, friends, and neighbors.

Natives of a small isolated town defend themselves against strange underground creatures which are killing them one by one.

A suburban American family is being stalked by a group of psychotic people who live in the desert, far away from civilization.

A brother and sister driving home for spring break encounter a flesh-eating creature in the isolated countryside that is on the last day of its ritualistic eating spree.

A group of five college graduates rent a cabin in the woods and begin to fall victim to a horrifying flesh-eating virus, which attracts the unwanted attention of the homicidal locals.