My husband wanted to name our dog "something badass" like Skull or Killer. He doesn't like giving dogs human names, and he wanted something fun. I was not about to name our then-one-pound dog Skull or Killer, so I joked, "Gee, why don't we call her Megatron" (said with a TV announcer voice). It stuck! We call her Meg, but her legal name is Megatron. DH gets a kick of out telling his friends that she's named after a Transformers character, so it's all good with me.
P.S. No, I didnt' know that Megatron is the evil villain until after we had named her! lol