I honestly thought it had got to the point where Charles Darwin couldn't possibly rise any further in my esteem, and then I read this:
When [Darwin's] daughter Etty's cat got into the pigeon loft, he untypically had it killed.
Wonderful! Better still, he had it replaced with a fox terrier (of all dogs) named Polly.
(I am so not a cat person.)
Update 28-Aug-2012: The original Telegraph article which cited this cat-killing anecdote was a review of the book Darwin's Garden: Down House and The Origin of Species by Michael Boulter. If you read my own subsequent review of the same book, you will gather that I am inclined to disbelieve some of the anecdotes it contains. I shall continue to search for a source for the cat story, but, in the meantime, I would advise you to take it with a pinch of salt.
Update 28-Aug-2018: It took me exactly six years, but I did eventually managed to conform the cat story. More here »