Updated description by GoldenHelmet
- Create a texture pack with different textures for different zombie villager professions.
- Apply the texture pack to a world, and open the world.
- Spawn zombie villagers.
Adult zombie villagers' profession textures match their professions.
All adult zombie villagers use the farmer profession texture.
Zombie Villager Spawn Egg
The Zombie Villager Spawn Egg only produces farmers... and baby ones spawn with no profession.
Found using custom texture pack because vanilla zombie villagers have no profession texture.