Minecraft/Iron Golem

This mob is found in villages, considered a protective guardian for the villagers 24/7 What hostile mob does it not kill ? Despite it killing most mobs, it does not attack creepers for somewhat reason. Resources and how to receive them? •Want iron? Its easy! Get 3 blocks of any material, get close to an Iron Golem and then jump and stack them underneath yourself (4 may be necessary)and attack it(a weapon like a stone sword or something as powerful is needed should you have one) and thats it! Approx. 4 irons and a rose are earned. •Need security?They are also craftable