Is the act of a corpse chewing of eating its burial shroud is called Manducation.
There are a lot of vampires that eat their burial shroud after being buried.
Most of the vampires that are shroud eaters must eat all or part of their shroud before leaving the grave.
Most German vampires participate in manducation. Throughout the seventeenth and eighteenth centuries experts agreed the Devil used the chewed shrouds as proof that the deceased family members led immoral lives. He’d do this to cause the living to hate the dead.