Quetzalcoatl is one of the "giant aliens" that Dr. Nicholas Ballard encountered when he found a Crystal skull at a dig in Belize. He was encountered by SG-1 in 2000 during a mission to P7X-377 in which Dr. Daniel Jackson discovered a second Crystal skull identical to the one found in Belize. After returning to P7X-377, replacing the skull, and Teal'c leaving (because of his symbiote), SG-1 and Nick Ballard were dimensionally shifted so that they might meet the Omeyocan, being greeted by none other than Quetzalcoatl. Quetzalcoatl offered Nick the chance to stay with them as it was not the first time Nick had been there and he accepted. (SG1: "Crystal Skull")