Cavey Jr. becomes Captain Caveman 's sidekick after his birthday party .
Cavey Jr. helps his dad fight Dr. Icemare : a weatherman who is stealing rock - fridgerators to make Bedrock cold .
Cavey Jr. becomes Captain Caveman 's sidekick after his birthday party and helps his dad fight Dr. Icemare : a weatherman who is stealing rock - fridgerators to make Bedrock cold .