As I mentioned in one of my most recent articles (most recent here being a relative term...) Doctor Who as a whole is specifically designed to be as weird as possible. Or to put it in a slightly more up-with-people kind of way, Doctor Who was specifically created to be a program that showed us things that no other program on television could, which is why the theme music was deliberately realized by the lovely and extraordinarily talented Delia Derbyshire to sound as unlike anything you'd ever heard anywhere else in the world. Yet it's really a shame that over the years the style of the theme tune has fallen into sounding exactly like most other sci-fi theme songs (full orchestra, a bit military.) But that's another discussion for another day. So given that the initial to do list for the show was - 'Step One: Show lots of weird things', and that the show initially ran on that premise for a good 26 years* it's going to have a thing or two that makes you question the sanity of the people involved.
*or 21 good years and 5 that were OK. I don't have 5 specific seasons in mind, I'm just playing the odds. That said - here are the top 10 weirdest moments from the original run of Doctor Who (1963-1989). These are of course subjective. Your choices might differ. 48-26 year old spoiler warnings.
10. Everything about The Zarbi
Let's mention here that this story featured Martin Jarvis as one of the Menoptera, which means that the Zarbi actually manage to be weirder than The Governor of Varos, unsuccessfully trying to 'Vogue' while dressed up as a gigantic butterfly. Back when The Web Planet first came out on VHS, I immediately sat down to watch it with a friend of mine as I had warm and fuzzy memories of seeing the story on public television even further back when. The moment that The Zarbi appeared on screen he christened them the 'P-Ants', declared them the best thing ever, and vowed to never watch another Doctor Who that did not include them. (I had a similar reaction to the Adherents of the Repeated Meme, now that I think about it.) I had to break it to him later that this was the 'P-Ants' one and only outing, which was sad for all involved. I'll leave you with this summation- A gigantic fiberglass ant. With ballet dancer human legs sticking out of very obvious legholes. Who clearly can't see a thing because they keep running into everything. And then they start making that noise... Steven Moffat - we demand that you put on P-Ants! Why do I feel like I'm not the first person to use that sentence...