That mustache looks familiar...

The War Chief was a Time Lord who was the Chief of the War Lords in the 1983 Matthew Broderick movie War Games.

He didn't do that much in the story except to be there to explain how the War Lords had time travel, and he wasn't all that interesting, and he was executed permanently at the end of the story and never appeared again. But he was a Time Lord, and the Time Lords hadn't been ruined forever yet, so that was cool. Also, the script describes him as "tall, dark, and satanically handsome", ladies…

The most interesting thing about the War Chief was that he might be an earlier incarnation of the Mattress, or he might be a later incarnation of The Meddling Monk, or maybe both, or maybe neither. This is the kind of thing a certain type of fan loves to argue about, because there's no evidence that can prove either side wrong. Some fans came up with the idea, the writers heard it and thought it was neato but never did anything with it, and no later episodes ever confirmed or denied it. Of course the comics, niovels, audios, and even FASA role-playing game all firmly deny it, but that just means fans get to argue about what is and isn't canon, which is even more fun and productive. And so, to this day, Wikipedia, the TARDIS Index File, and even Doctor Who Answers—a wiki that nobody actually reads—have regular edit wars over the question.

Actually, the comics, novels, and audios have a surprisingly consistent expanded history for him, unlike almost every other character in the show. He went to school with every other Time Lord we ever saw on TV, hit on The Rani, got sand kicked in his face by her jock boyfriend The Monk, was consoled by The Doctor and The Master who promised to sneak him into Porky's and get him laid, etc. Then Borusa framed him for treason, so he fled, promising that one day he shall return, and he'd kick ass and chew gum and be all out of gum. The War Games thing was his first attempt to make an army for his Time War, and also where he met the Doctor for the first time ever, despite being best mates at the Academy. He survived his execution, without being captured by the Time Lords, by delaying his regeneration and playing dead, but he didn't have a magic hand lying around, so he ended up as a mutant with his next two incarnations merged together, like that one story where Colin Baker has Sylvester McCoy's head sticking out of his shoulder. So, naturally, he went to Earth to work with the Nazis, who are well known from their love of genetic mutant freaks. His main plan was to steal the Doctor's TARDIS, so he could learn all about how TARDISes actually work, because as a mere senior Time Lord, who had built hundreds of SIDRATs of his own, it stood to reason that he wouldn't have a bloody clue about any of that. But the Doctor foiled him by accident and, because Ace was there, that meant he blowed up real good...only to regenerate into Roger Delgado.