I was inspired by the thread on Norse mythology. I’m thinking more along the lines of Greek/Norse/Celtic mythology, but I’ll leave the definition broad. If you want to include stuff from the bible or whatever, that’s fine with me.
My favorite is Hermes. He’s just a really cool character. A messenger who’s a bit of a prankster. What’s there not to like?
Also, the crazy inkeeper in the story of Theseus. He had only one bed. If someone was too short, he’d stretch them on the rack, and if they were too long he chopped off their legs.