Player view is sometimes obstructed by a giant texture plane that appears to be based on a player or mob's head texture, rendering the game very difficult to play.
This occurs whenever a mob wearing armour, such as a zombie or skeleton, is within the player's FOV and within approximately 4 chunks, regardless of whether the mob is hidden by blocks. The glitch texture reflects the light level around the mob, and may glow purple if the mob is wearing enchanted armour.
Moved to the correct project.