The Caveman is the main antagonist of the Scooby-Doo, Where Are You? episode, "Scooby's Night with a Frozen Fright".
Scooby's Night with a Frozen Fright
While fishing at a beach, Shaggy Rogers snagged and pulled ashore a giant block of ice containing a frozen caveman. Velma Dinkley recognized it as a 2,000,000-year-old caveman discovered in the Arctic and washed over the side of a research vessel during a storm. The kids took it to Oceanland and left it with two scientists, Professor Wayne and Professor Engstrom. After they leave, someone turned a space heater onto the caveman.
At the malt shop, Shaggy remembered that he left his fishing tackle at Oceanland, and the gang returned to pick it up. They found the doors ripped off their hinges, Wayne's torn parka, and the caveman thawed out and missing. The phone was broken, so the kids decided to investigate. They followed giant caveman tracks to the dock, where they saw Engstrom working a strange device and seemingly talking to a porpoise. He took fright and fled into a shack when he heard Scooby creeping up on him. When Fred Jones opened the door to the shack, they discovered the angry caveman, who chased them all about Oceanland.
After they escaped, Velma found a map showing the currents off Oceanland and an object anchored offshore. She, Shaggy and Scooby took a row boat out, where they found a fishing boat. While investigating, they got locked inside a room with an ice machine that was churning out giant ice blocks full blast. They escaped just before being crushed by the ice, only to find that their boat had been scuttled, so they paddle back to shore on an ice block.
Freddy resolved to catch the caveman and had Shaggy and Scooby (dressed as fish) lure the caveman to a spot where he and the girls could drop a net on him. But Daphne fell, pulling everyone else down into the net. The caveman chased them again, but was caught when he fell into the tank holding a giant clam. They pulled him out and unmasked him as Professor Wayne; Wayne had heard about the loss of the Arctic caveman and had constructed his own "frozen caveman" at the fishing boat, with the intent of letting it drift down to Oceanland. After its recovery, he melted it with an electric heater and disguised himself as the caveman with the idea of getting rid of Ingstrom and stealing his invention: a revolutionary marine life communicator. After Professor Wayne was taken away by the sheriff, Mystery Inc. headed to the malt shop where Scooby-Doo used the caveman costume as a dance partner.
Scooby-Doo! Night of 100 Frights
In Scooby-Doo! Night of 100 Frights, The Caveman is one of the monsters brought back by the Mastermind.
In Scooby-Doo! Unmasked, The Caveman is the third boss.