if you are sleeping on a bed while wearing a dragon head, you kind of just see the inside of the dragon head while in the sleeping perspective, this takes a LARGE amount of the screen, and once you wake up everything will go back to normal(the bug will happen again if you try to reproduce it don't get it wrong).
the amount of the screen that the bug will take is dependent of how open the dragon head mouth is open.
I have verified the bug and done multiple times before submitting, these are the steps to reproduce the bug.

Steps to Reproduce:

1. wear a dragon head.
2. wait for nighttime(can skip if already at nighttime) or go to nighttime through commands.
3. sleep on a bed.