- "I just want to live, I want to experience the universe and I want to eat pie."
Urgo was the artificial intelligence (AI) of a microscopic implant which was embedded in the brains of SG-1. The implant was designed to be an information and experience accumulator using direct electrical interaction with the host brain. Through a design error, this direct brain interaction also allowed Urgo to modify the perceptions of his hosts to visually and auditorily manifest himself. Essentially, Urgo induced a controlled hallucination in which he took on the appearance and voice of his creator, Togar.
Urgo was placed into the brains of SG-1 on a trip to the planet P4X-884. The memories leading up to and following the implantation were wiped from SG-1 before they were returned to Earth. Urgo began modifying the senses of SG-1 to entice them into experiencing whatever Urgo currently wished to learn about. At first Urgo implanted a subconscious desire to eat, and modified the experience of taste to make it more enjoyable. Soon after, overcome by the boredom, he began to speak and interact with SG-1. All members of SG-1 heard and saw the same hallucination, indicating the implants worked on a wireless network and share information. Of course, no one else could hear or see Urgo which made for several awkward briefings until Major General George S. Hammond and Dr. Janet Fraiser became convinced of Urgo's existence.
After hours of Urgo constantly asking questions and generally annoying SG-1, Major Samantha Carter tried to destroy him with an Electromagnetic pulse. Though initially effective in disabling Urgo, the implant automatically rebooted and he quickly returned. At this point, an exasperated SG-1 decided it would be necessary to go back to P4X-884 and negotiate for the removal of the implant by its creators.
Urgo tried to persuade SG-1 to not go back to his planet, saying that his creator was a mad man who would scoop out their brains to retrieve the implant. After initiating contact with Togar, SG-1 learned that Urgo's interactive behavior was actually an error. This prompted Urgo to admit he was scared of death, that he didn't want to return to his creator and be shut off. SG-1 decided it wouldn't be morally right to simply end Urgo's life, so upon returning to P4X-884, SG-1 persuaded Togar not to destroy Urgo, even though this meant implanting Urgo into his own brain. (SG1: "Urgo")
Urgo seems childish, always wanting to do fun things and play games. Even with a limited ability to read the thoughts of his host, he asks many questions. He is also very persuasive, although he can't outright force people to do what he wants. He is very persistent and nags until he gets his way. He can change his visual size and appearance at will, but prefers to look like his creator. (SG1: "Urgo")
Behind the scenes
There are very few scenes between Teal'c and Urgo, since apparently Christopher Judge could not maintain the requisite solemnity for his character when faced with the often ad-libbed antics of Dom DeLuise.
The name of the character "Urgo" is possibly a reference to the famous quote "Cogito ergo sum" ("I think therefore I am") by René Descartes, given the issues of an artificial intelligence's right to life addressed in the episode.