Zombie Equipment

Zombie equipment (net.satisfy.foundation.entity.equipment)

Give spawning zombies items from your mod, such as a hat or a tool. Foundation ships one mixin for all mods, so your mod needs none. Since Foundation 1.0.5.

Register in your mod's common init():

ZombieEquipment.add(0.03)
        .slot(EquipmentSlot.MAINHAND, ModItems.PITCHFORK);

ZombieEquipment.add(() -> MyConfig.zombieHatChance)
        .adultsOnly()
        .slot(EquipmentSlot.HEAD, ModItems.COOKING_HAT);

Method	Does
add(chance)	new outfit with a fixed chance (0 to 1)
add(() -> chance)	chance read from your config on every spawn
slot(slot, item)	item for an equipment slot, several slots per outfit are fine
adultsOnly()	baby zombies don't get it

Every outfit rolls on its own when a zombie (also husk and drowned) spawns. Items stay with vanilla drop chances.