Dr. Millard Gagnon was a scientist employed by Venture at the V-22 testing facility, also known as the Lodge. He, and his assistant Brigette, came into possession of a Xenomorph egg thanks to the company's spy Tamar Prather.
When it was agreed they would use a human volunteer as a host, he chose Hassan Bagrov, a technician who had previously been a test subject in exchange for credits. Gagnon's choice in host would bore unexpected results as the host retained traces of necrosis from a previous experiment, which greatly affected the resulting Xenomorph specimen.