Jack Skellington MeUndies Underwear for Women - Bundle with 1 Pair of Size XL Bikini Panties for Teens, Women Plus Button | Nightmare Before Christmas Undergarments. This Nightmare Before Christmas underwear set include 1 pair of size extra large MeUndies bikini panties featuring cute Jack Skellington artwork. These MeUndies Nightmare Before Christmas bikini panties are made of comfortable material and are great to wear all day long. Machine wash the MeUndies Nightmare Before Christmas underwear on cold to preserve the artwork of Jack Skellington. Officially licensed Nightmare Before Christmas MeUndies underwear for women. Set also includes a separately licensed button.