This happened about three weeks ago, August 15th, around 7:30pm. I was walking the Yorkshire Moors near Hebden Bridge - lovely evening, clear skies, still quite light out. I was alone, which in hindsight maybe wasn't ideal.
I saw what I can only describe as a tall, impossibly thin figure standing about 200 metres away on a ridge. Humanoid shape but the proportions were completely off - arms too long, body too straight, movement too fluid. It didn't walk, it kind of... glided, for want of a better word. No distinct head shape that I could see. The whole thing was maybe 8-9 feet tall.
It noticed me looking at it. The moment I made eye contact (or what felt like eye contact), it turned and moved away at speed that no human could manage over rough terrain. Just... gone. Took about four seconds to disappear into the hills.
I felt absolutely terrified. Shaky for hours afterward. I've never experienced anything like it. I'm wondering if: (a) I hallucinated something (unlikely, I was perfectly alert), (b) it was a very tall person in unusual clothing (possible but their movement was genuinely unnatural), or (c) something genuinely anomalous.