John

John was a Being of Light whom informed Apollo of the situation on Terra, hoping that Apollo would be able to resolve it peacefully. His chief concern was that any outcome concerning the planet would have drastic intergalactic consequences. Although we don't know what those were, it is presumed that the Terrans are instrumental in some sort of long-term plan.

John told Apollo that his "physical appearance" was a reflection of intelligence (i.e., spirit), and that he could do nothing outside the colossus; ergo Apollo's assistance. John, like any other Being, apparently could cause memory blocks and unblock them, as well as work through them by giving them a protective aura. He also commented on the fact that he needed humor in order to communicate with other "child" races.

In the apartment of Brenda Maxwell, Apollo was talking to John, who couldn't be heard or seen by anyone else; thus Apollo, under the guise of Charlie Watts, was made to look a bit mentally unstable. John was instrumental in also recruiting Starbuck, who could hear him, but only see him after John gave him the protective aura.

Ironically, John's actions of having Apollo solve the situation peaceably were to no avail as the Galactica's intervention forced the Eastern Alliance to accept the peace accord from the Nationalists. John did admit, however, after some pestering from Apollo, that Terra wasn't Earth and that they still had a long, interesting journey ahead of them. (Experiment in Terra)

Portrayed by Edward Mulhare

Notes

Evidently, the John character goes against the pre-established information given in "War of the Gods", for Iblis had a physical body outside of any Ship of Lights or anything remotely similar. This being the case, either John was lying or the Beings that are inclined to pure good do not have the capacity of a "physical" body outside of the Ship of Lights.

Additionally, it is interesting that Starbuck managed to hear John, albeit unable to see him until John touched him. (Yes, John touched Starbuck within the physical laws of the Universe, as Starbuck reacted to it.) Disproving yet again that he (and presumably other Beings of Light) can attempt some form of physical contact, at least on some level. Although Starbuck's past experience (War of the Gods) with the Beings may have something to do with it...

There is the possible hypothesis that John happens to be a young, maturing Being that could only be hundred or so yahren old. Thus, to use an antiquated Earth belief, John may not have his "angel wings". The Beings "angel wings" may quite possibly be similar to Iblis' demonstrated attributes, in the manner of physical contact outside the influence of the Ship or similar environment. Still this is not part of the canon, regrettably, and also proves that the writers of this Terra "mini-arch" didn't know where they were going -- at least in this writer's point of view.

People tend to ignore certain instances in the episode (Experiment in Terra) that featured John (Edward Mulhare), neither being fan favorites. There is particular chaff concerning the inconsistencies between this episode and the information provided in "War of the Gods" (one of the top fan-favorite episodes).