I only ever managed to kill the Iron Golem once - it lunged at me and off the tower, but I'd rolled/dodged and fell off my self. Luckily it registered it's death before mine so counted as a kill. Think my build was pretty bad at the time and didn't ever give it another go!
I enjoyed it, then I accidentally found Iron Golem.
Jokesboss, so easy.
Now I'm in Anor Londo.