Cro (1993)

Dr. Cecilia and her assistant Mike discover a glacier containing a mammoth, Phil, frozen solid. After being defrosted, Phil narrates the tales of CRO, an inquisitive Cro-Magnon boy. CRO uses applied science and enlists the help of a highly intelligent group of mammoths to aid a blundering clan of Neanderthals. It's an exploration of the Ice Age in an animated comedy/adventure format.