Hollow Festival
During the human days of October, the Glassheads celebrate the Hollow Festival!
During this time, Mother Glass creates Hollow Glassheads and Hollow chunks - all each with a one-way ticket to the Glowing Glassyard, a special location deep in the Midnight Forest.
Glassheads from all over Glassgland teleport here to dress up, give out candy and celebrate the coming of their Hollow cousins. Sweet-giving was originally to bribe the Hollow Glassheads not to scare them, but as now a common celebatory practice.
Hollow Glassheads often have unique traits (found in here) and always have generally spooky appearances.