- Do you know the average human uses less than 10% of his brain? I use 98.6% of mine.
- —Klaus Mensa
He was a dangerous man with great brain power, so powerful that he could control items by telekinesis. His enormous head gave him the nickname "Fathead", which he always hated and physically harmed anyone who called him it.
He was also one of the few villains to know Superman's true identity, but when he lost his brain power so did his knowledge.