Etahy was a Volca who was native to the planet Kar'tek, and the father of Aemon. Shortly before the Tau'ri visited his home planet, Etahy and his family were being chased by Mars' Jaffa and discovered the long lost Stargate. Though they were safe in the cavern surrounding the Stargate, Etahy's son decided to phase through the wall to see if the Jaffa were still following them, against Etahy's wishes. It was because of this that the Jaffa were able to ascertain their location of his family. Though his son was captured, Etahy and the rest of his family were able to escape.
Etahy was seen by the M.A.L.P. sent to Kar'tek by the Tau'ri and it was because of his unique phase shifting ability that they decided to come to the planet. Etahy soon met with SG-1, but the group were attacked by Mars' Jaffa and only Etahy and Daniel Jackson were able to escape. Etahy took Daniel to meet with the Volca's hero, Ulysses, who gave Daniel a piece of phase shifting technology which worked in the same way as the Volca's natural ability. The duo were then able to attack Mars and his contingent of Jaffa, freeing both SG-1 and a number of Volca. It was during this attack that Etahy phased his hand into Mars' Mar'kak host, supposedly killing him; what none knew was that Mars' symbiote had in fact survived. (SG1: "Fall of Rome")