Heraclitis
Died covered in cow shit in 575BCE
Heraclitus was a very popular in ancient Greece, and at some point in his life, he developed a painful condition called ‘dropsy.’ According to the folk remedies available, covering yourself in cow dung and resting in the sun was the answer. It wasn’t, and he died.
There is a video of this on YouTube (honest). You can tell he was afraid to jump, but his handlers kept telling him it was too late to back out.
So all the way down, when he knew he was going to die, at least he had the satisfaction of being able to yell "I told you so!"