A video featuring a mysterious, dark creature instantly went viral overnight as locals spotted something massive swimming in the Chena River of Fairbanks, Alaska.

Many have described the creature as an "Ice Monster" referring to Scotland's famous Loch Ness Monster. There are theories that this is a giant Arctic crocodile or even a "zombie salmon."

Last week, a local official with the Alaska Bureau of Land Management in Fairbanks was inspecting the ice on the river when he noticed something moving up in the river and whipped out his camera to capture this strange creature.

At first glance, it appears as if large pieces of ice are moving sideways on the river. However, a dark figure is seen under this icy river surface.

 According to the Bureau of Land Management of Alaska, the official did not proceed to investigate since it was somewhat far out in the middle of the river. This video was taken by the BLM Fairbanks District Office facing downstream. However, the bureau said that it is not sure what the creature is. 

The video has received more than 800,000 views and has been shared online over 5,000 times since it was posted on the Bureau of Land Management of Alaska's official Facebook page last week.

The Alaska Bureau of Land Management added some creepy music to the 25-second-long footage.

Commenters have noted that it could be an Alaskan sturgeon, or a bull shark or even a prehistoric predator. Some, however, say it is not a fish but rather a moose hide or debris that is caught in the current.

On, November 1, officials at the Alaska Bureau of Land Management announced that the mystery had been solved. They say that experts at the Department of Fish and Game of Alaska revealed that the most likely explanation for this creature is a "frazil ice" which has been stuck to a rope and most probably caught on a bridge pier.