Jack Skellington from "The Nightmare Before Christmas" makes a brief cameo during the credits. In the scene going down in the ground, Jack's skull appears among other skulls. He is also seen as a topper on the antenna of the juvenile justice van.
The soundtrack is comprised of black-fronted rock bands.
To prepare their voice roles of Wendell and Wild. Key & Peele had to watch a lot of Abbott and Costello comedies.
Kat and Delroy both wear Fishbone t-shirts. Director & writer Henry Selick directed Fishbone's 1985 video Party at Ground Zero.
The title characters are not only voiced by Key and Peele, but the characters are also designed to resemble them,