A Goa'uld who long ago discovered a healing device created by the Ancients and used it to develop the Goa'uld's sarcophagus technology. He is probably the same figure as "Chak," described by ancient Earth mythology texts as the Mayan god of rain.
Long ago the System Lord Anubis went to war with Telchak over possession of the Ancients' device. Telchak lost the war, but Anubis never managed to acquire the device for himself. Telchak is probably responsible for hiding it on Earth, beneath a waterfall in Honduras -- where it became the source of the Fountain of Youth myth.
Telchak's ultimate fate is not known, though he no longer appears to be alive and active on the galactic scene.
Evolution, Part 1 - Selmak speaks of an era when Telchak and Anubis were bitter enemies.