When people first encounter the Mammoth, they discover that it was frozen in a block of ice, and people also discover that it was the museum's most notable exhibit. The film centers around the idea of an extraterrestrial being taking possession of the Mammoth corpse, and then proceeding to go on a killing spree. When the United States government was alarmed about this bizarre occurrence, they were fully intent on sending a nuclear bomb into the heart of the city in order to kill the prehistoric animal. With the threat of the city's destruction on the horizon, our protagonists had to find a way to subdue the beast before the bomb arrived. They ultimately decide on luring the prehistoric beast into a liquid nitrogena trap, and Simon sacrifices his life in order to stop the Mammoth.
The re-frozen Mammoth is later returned to the museum, and Simon's frozen body is taken into the government's hands.
Behavior and Nature
Mammoth actually a soulless being that borned from a mammoth's stuffed corpse that possessed by the alien lifeform after the alien crash landed on the museum as desperate attempt to adapt planet Earth. But unfortunately, though possession on the mammoth corpse seemingly help to adapt our planet, this effort drove the alien insane and suffer the hunger of other lifeform's lifeforce that it incapable to quenched. This is why it was gone for killing spree.
The Mammoth possessed the ability to suck out the lifeforces of its victims. It does so through its trunk.