Different monsters have been "trendy" during different time periods. It felt like vampires were everywhere for a while such as Interview with the Vampire and other Anne Rice works, Buffy the Vampire Slayer, Bram Stoker's Dracula, From Dusk til Dawn, etc. It was on the downswing when Twilight and True Blood hit and faded out pretty quickly after that. Then suddenly it was zombies with The Walking Dead, Warm Bodies, (2004)Dawn of the Dead et al, 28 Days Later, Resident Evil, World War Z, etc. I think Werewolves just had a little moment of popularity in the 80s with American Werewolf in London, The Howling, Teen Wolf, etc. London happened to be in vogue during the same period.

I had no idea this was an actual song. My dad taught it to me and I used to sing it with the neighborhood kids, but never heard an actual recorded version. Super interesting!