Gonds and Koyas(speaking Konda language)provide invaluable informationin deducing the prehistory of Telugu are closely related tribes. Gonds have an interesting story about the origin of their tribe.
It also matches the story Koyas have
to say about their origin. Once upon a time there were 1600 crores of
Koyas at Dhavalagiri. They were very dirty and never used to take
bath. Mahadeva got disgusted at their dirtiness and jailed them in a
cave. However Parvati was very fond of them. She did penance and got a
son called Lingo. Linga prayed Mahadeva that Koyas should be released.
Shiva would release them on the condition that Lingo performs all the
adventures that Shiva asks. Once Lingo performed all of them
successfully, Shiva had to release them.