The Neanderthals are exhibits in the Museum of Natural History.
There are four Neanderthals that are on display at the Museum of Natural History.
There is a part on the Manual that says "Distract the Neanderthal Men once an hour. If they complete sharpening their spears, they will hunt you."
During Larry Daley's second night, he gave them a lighter claiming that their quest for fire is over. This later caused one of the Neanderthals to catch fire causing Larry to put it out with the fire extinguisher. When the window was opened by Dexter, one of the Neanderthals got out of the window. Upon being alerted by the bronze statue of Christopher Columbus, Larry tried to get it back in only for it to turn to dust upon the sun rising. The incident with the Neanderthals had nearly caused Dr. McPhee to fire Larry.
By the third night, the Neanderthals were shown fighting with the other exhibits in the museum until Larry broke up the fight with the help of the Easter Island Head. The Neanderthals were paired with Christopher Columbus to help them capture Cecil Fredericks, Gus, and Reginald. The Neanderthals and Christopher Columbus were successful in capturing Reginald.
The next night, the Neanderthals took part in the museum party. One of the Neanderthals was shown drinking from the fire extinguisher.
The Neanderthal exhibit was given a new addition in the form of Laaa, a Neanderthal that resembles Larry.