Diamond Golems spawn rarely in NPC villages, along with 4 other Iron golems. They have a simmilar AI to an Iron golem, but they will go after any hostile mob. They are also harder than an Iron Golem, dealing 300 hearts of damage (an OHKO without a lot of Health EXP), and has 90000010 hearts (Yes, it is WAAAAAAAAAAY over 9000!). They have the same drops as Iron golems, But instead of Iron, They drop 30000-500000 diamonds. They also deflect arrows, can breath underwater, and have fire resistance plus blast resistance, thus nullifying Explosion damage, Lava damage, and fire damage. A Diamond Golem's range of attack is 20 blocks up plus down plus left plus right.
Building one is similar to building Iron Golem but with Diamond Blocks. However, they can destroy Monster egg stone types without awakening the monster inside and hold roses. Plus, they have an aura similar to a charged creeper and it spans 20 blocks the same as its attack range. Anything that is passive and not targeted by a Diamond Golem Gets fire resistance, blast resistance, and nothing can explode, nor can fire spread, making them a great way to protect your house.
The Diamond Golem looks like an Iron golem, but with colors of a diamond block. There is also no moss; the moss is replaced with ice. It also has blue-purple eyes.
Arrows are useless to Diamond Golems. Mob grinders don't work because Diamond Golems can breathe underwater. Their health is HUGE as well as their range, TNT damage is nullified, fire aspect does not work, and they can OHK an Enderdragon! So how do you kill this thing? Simple; you don't unless you use cheats or a powerful weapon because they are not the bane, but the Mr. Freeze of Harskadom's Existence! (Well you actually have a 1% chance of beating him with an emerald sword, but good luck, it's unknown if they can hurt you in creative) But Chuck Norris has a 30% chance of beating him. An Armageddon Blade is recommended.