I don't know about creepy, but one of the most stupid was a Seventh Day Adventist. I guess like Mormons, there's some 19th century prophet some of them are supposed to follow: How to dress, who to marry, that kind of thing.
My friend said, "Oh I don't follow that text because it's like 150 years old so obviously outdated. I just follow the dietary commandments in the old Testament.
Creepy, hmmm... I'll have to give it some thought. In its own special way, most anything a Theist says is creepy.