Leefa

Leefa was one of a type of monkey that existed during the time when Silurians lived on Earth. He was the pet of Kaya. When a little planet approached the Earth, the Silurians were forced to hibernate en masse. Kaya was sad to hear she could not bring her pet monkey Leefa under the surface, and she spent the weeks leading up to their departure playing with Leefa and attempting to teach him how to talk. When all of the Silurians left the surface, Leefa shouted "Kaya!" into the distance.

As he eventually learned how to talk, Leefa's species were presumably ancestors of humanity.