That was hilarious and Happy Clock Day! The best joke was easily the one at the end. There's a more realistic reason why he would die. Millions of years ago, the levels of oxygen were higher. That allowed for organisms to become larger because of how they could breathe. He couldn't adjust to the lower levels of oxygen.
I think the disease bit makes sense too. It's just not how I would have approached it. Are you missing some teeth? I loved the live-action bit the best. The animation is fine.