Why

He was a cannon

One used in the revolutionary war and was shot out of a turret when operating for the British.

That's what they get for thievin'

That saying was on the wallpaper all over my room when I was little...

I find it strange how pretty much every classic thing to teach your kids is originally about death or something equally as creepy. In most original fairy tales there was suicide or rape or death of some kind; most nursery rhymes are based around death.
Three Blind Mice is about noble protestants during the reign of Mary 1. They were burnt at the stake.
Here We Go Round the Mulberry Bush is about female prisoners at some prison I don't remember the name of. They would exercise around a mulberry tree at night.
Oranges and Lemons is about executions (pretty obvious though, when you think about the lyrics.)
Ladybird Ladybird is about Catholics who refused to attend Protestant services.
There are heaps more, but I don't want to fully ruin anyone's childhood.

I snorted