I've tried googling, and I got some people saying "put a helmet on them", but for me, it doesn't work. The helmet doesn't appear. This might have something to do with how the new Minecraft scripting NBT thing works?
The command is something along the lines of:
/summon Zombie ~ ~ ~ {Equipment:[{},{},{},{},{id:minecraft:stone_button}]}
Best Answer
The problems with your command are:
Equipment
should beArmorItems
The fixed command should be: