If you removed the pumpkin of the snow golem, then you exited, then you entered the world, the pumpkin will go back again at the snow golem's head.
Steps to reproduce:
#1. Spawn a snow golem
#2. Remove the pumpkin.
#3. Exit, then enter the world.
#4. You will notice that the snow golem have a pumpkin on its head again.
Device: Lenovo A5500-HV