The Loch Ness Monster it's not.

But an unusual-looking snake spotted in a central Illinois lake has prompted excited speculation, as well as a search in advance of the upcoming Independence Day holiday.

A woman who lives near Lake Springfield took a photo in April of what appeared to be a large, yellow snake — its head above the water and its body beneath it.

Lake manager Michelle Nicol said the snake hasn't been seen since at the popular holiday destination for Springfield residents, but authorities are still keeping an eye out for it.

Nicol also appealed for help in locating the reptile, which may not be native to the area.

"If anyone sees anything, please take a picture and send it to us," she told The (Springfield) State Journal-Register on Friday. "And we want to stress: Please don't dump your exotic animals or fish in the lake."

Some residents believe the animal is an exotic python released by an unscrupulous pet owner. Others think it might be native to the region, possibly a northern water snake.

Either way, some have gone so far as to dub the mysterious creature "Nessie," in homage to Scotland's fabled Loch Ness Monster.