In Up, Charles Muntz is the main villain. At the beginning of the movie, he is shown when Carl and Ellie are young - he's an adult already. Fast forward to when Up takes place. Ellie has passed away, Carl is in his seventies, and Charles... doesn't actually look that much older. He looked about the same - or even more spry - as Carl.
Do we have any idea how old he was at any time?