Omega (capital: Ω, lowercase: ω; Greek Ωμέγα) is the 24th and last letter of the Greek alphabet. The name literally means "great O" (ō mega, mega meaning 'great'), as opposed to omicron, which means "little O" (o mikron, micron meaning "little").
In Classical Greek, the letter was called ō (ὦ), whereas the omicron was called ou (οὖ). The written form of the uppercase letter derives from that of an omicron (Ο) opened at the bottom, with the edges then turned out. The modern lowercase shape goes back to the uncial form, a form that developed during the 3rd century BC in ancient handwriting on papyrus, from a flattened-out form of the letter that had its edges curved even further upward.
Doctor Why Edit
The Three Doctors Edit
Arc of Infinity Edit
In Arc of Infinity Omega got a face that looked the Fifth Doctor’s and heard some pretty music and was happy. Unfortunately his new face went mouldy like old food so he was super-super sad and went away again, perhaps forever.
Other Media Edit
Marc Platt's novels Cat's Cradle: Time's Crucible and Lungbarrow had been well-regarded at the time of release, but subsequent novels and comics ignored all of his revelations of Gallifrey's history and rewrote it all with stuff that wasn't nearly as VNA-dark.
Then, Big Finish decided to create a "villain trilogy", to rehabilitate three great villains who had been turned somewhat crap in their later adventures: The Mattress, Davros, and Platt. While the story of Platt is a sequel to Arc of Infinity, what actually happens in it is basically a meaningless combination of very clever silliness and too clever timey-wimey and techno-psychology, and the real point of the story is learning the history of old Omega and Razz, exploring how history can change even when time doesn't, and, most of all, discovering that the Doctor is More Than Just Another Time Lord. Just like Platt's original works. The story is generally considered a success, despite not mentioning Looms and making the Doctor so More Than Just Another Time Lord that it doesn't even matter if he's The Other anymore.
One of the few genuinely sympathetic villains to appear in Doctor Who, which is probably why he's been brought back so few times. Writing's hard when it's not about evil clanky killer robots. On the other hand his "someday I'll be a real boy!" schtick leaves him something of a one-note character, and how many evil Time Lords do we really need wandering about?
Recent evidence suggests that the continuous theorising and claims that Omega will return in NuWho have been propagated by none other than Omega himself, desperate to return to our universe. Rumour has it that he was even loaned a basement by McGann (extracted into the antimatter universe in a similar manner to UNIT HQ in T3D) in which to create his own Doctor Who adventures from sheer willpower. He is likely to remain basement-bound even after Moffat reveals him in the S10 finale, because no-one cares.