On Halloween night, monster sightings in Illinois will go through the roof--little goblins and ghosts and ghouls will abound in every neighborhood. But Illinois also has its fair share of sightings of monsters that don't go door to door asking for candy.

Believe it or not, Illinois is rife with reported sightings of monsters ranging from ferocious creatures hiding beneath murky waters to towering humanoid-like beasts seen wandering the woods and river valleys in remote and rural parts of the state.

Whether these stories derive from local legends, folklore, myths or overactive imaginations, you definitely wouldn't want to stumble upon one of these nightmarish Illinois monsters.

1. Sasquatch (aka Bigfoot)

Illinois has the most reported Bigfoot sighting of any state east of the Mississippi, most of which are concentrated in remote and rural parts of southern and central Illinois.

The earliest documented sighting was in 1883 in a wooded area near Centreville.

2. The Enfield Horror

In April 1973, numerous sightings of a deformed creature having T-Rex-like arms with short claws, pink eyes, gray, slimy skin and three legs attacked a young boy as he was playing in his backyard. Later that evening, the bizarre creature tried breaking into a neighbors home, where it was shot by a man named Henry McDaniel with a .22 caliber pistol. A news director for WWKI Radio supposedly taped the monster's screams as it ran off, covering 50-75 feet with just three giant leaps and vanished.

Back in the 1940s, similar sightings were reported in the nearby town of Mt. Vernon, leading some to believe this creature reappears every few decades and will return again.

3. Thunderbirds

There have been many alleged sighting of Thunderbirds in Illinois, which are giant birds with wingspans reaching up to 20 feet. One well-known local legend near the town of Alton is that of Piasa bird, a name given by the Illini Indians meaning "bird that devours men." Although it has been restored, there is a painting of the Piasa bird on a bluff that's believed to date back to the late 17th century.

In 1973, an incident occurred in Lawndale where two gigantic birds attacked a group of children, one of whom was carried off by the bird being being dropped shortly after. A man named Texas John Huffer is said to have filmed a group of these birds at Lake Shelbyville that same year.

4. The Farmer City Monster

A giant, humanoid-like monster with bright yellow eyes seen multiple times in the 1970s. The good news is it's seemingly afraid of humans as it runs away whenever spotted.

Sightings: Farmer City, Bloomington Weldon Springs State Park, Heyworth and Waynesville in the 1970s.

5. The Mad Gasser of Mattoon

The Gasser is described as a tall, thin man who wore dark clothes and a tight-fitting cap. While gas attacks were originally reported in Botetourt County, Virginia, a spate of them happened a decade later in Mattoon beginning in August of 1944.

Hysteria swept through Mattoon after numerous residents claimed to have been sickened by gas. Things got so out of control that the FBI took on the case, but the Gasser was too elusive and never caught by the authorities.

Check out five more ghastly monster stories at Reboot Illinois, including on that might be lurking just below the depths of Lake Michigan.

Sign up for our daily email to stay up to date with Illinois political news.