The God Complex centered around a minotaur who's a prison guard (at least I think that's what happened. I'm a little confused about the mechanics of it all, to be frank). But minotaur he was, with the usual trappings of horns and labyrinths and general menace.
But this bull-headed creature is no stranger to Doctor Who, whether we're talkingabout the original minotaur (The Doctor lent Theseus a ball of string, didn't you know) or variations thereof. Here's an overview.
THE MIND ROBBER
The Mind Robber is widely considered one of the most clever and imaginative episodes in the entire run of Doctor Who, tackling the very nature of creativity and fiction, and giving us fun set pieces like Rapunzel hooking up with comic book characters.
One episode of the story centers around a labyrinth populated by a variety of classical myths, such as a terrifying unicorn and Medusa. And at the center of the labyrinth, there is, you guessed it, a minotaur.
THE TIME MONSTER
Let me begin by saying that this story centers around something called the TOMTIT machine (that's what she said!). Blah blah Master/Doctor HoYay! plotty-cakes, and we all end up in Atlantis.
The magical plot device in this episode is guarded by the Minotaur in the heart of a maze, allowing the Doctor to continue his genocidal trend of eradicating all Minotaurs from the cosmos. You guys just need to see this episode, it's completely nuts. Sergeant Benton turns into a baby, and the Master hooks up with a Bond girl. I don't even know why the Minotaur is in it.
You do get this lovely "Doctor remembers his youth" scene though:
PELADON AND AGGEDOR
There's the actual minotaur. And there's Aggedor, who isn't technically a minotaur but has all the trappings. He brings us this wonderful scene in Curse of Peladon (Rule #21: The Doctor should never sing). This scene has the added bonus of perfectly encapsulating the relationship between the Doctor and Jo, who wanders through her episodes like she's on an acid trip. Skip to 1:21.
And then, rinse and repeat for Monster of Peladon (why they set two episodes in this horrendous storyverse is beyond me):
Wherein, somehow, Aggedor becomes a fire-breathing statue with a massive belly button:
HORNS OF NIMON
Nimon was of course referenced in The God Complex as a distant cousin of the minotaur in the new story. The Horns of Nimon is widely considered the nadir of the Tom Baker era, but I won't lie, I kind of love it.
Basically, an ambassador Nimon travels to a planet, pretending to be a God with advanced technology. There, it would convince worshipful residents to build a labyrinthine Power Complex to power a small black hole to bring in more Nimons. The Nimons would then drain all the locals of their life essence, and then move to the next planet as part of their "The Great Journey of Life."
It is suggested that the minotaur of classical myth was in fact a Nimon scout. Luckily, the Doctor and Romana (Romana, mainly) are there to save the day, leading to this great instance of "acting":
And there you have it! Minotaurs through the Doctor Who ages.