The skull bra was made by two cute little wood elves who got caught in Jeredith's flamethrower.

More comics about (and kind of about) Halloween!
#567; O Selfless Saviors
#767; The Old Farmer’s Lament
#774; In which Candy is Lacked
#838; The Lament of the Auteur
#593; In which Mike is Corporeal
• Emmy & the Eggs Part One / Two / Three