Animating the cheesy horror film that Norman is watching at the start of the movie was reportedly very difficult for the filmmakers, as they had to intentionally make a bad film (bad camera angles, poor focus, bad "acting" etc) while still working in the very technically demanding confines of stop motion animation
There is an after-credits scene showing in time-lapse the designing and construction on a workbench of the Norman character, which ends with Norman coming to life as if waking up from sleep and leaving the scene.
During the last few weeks leading up to the film's release, Laika sent 49 packages to 49 people (including Neil Gaiman and Kevin Smith and Jenny "The Bloggess" Lawson). Each package consisted of a wooden crate from "Blithe Hollow" full of "grave dirt" which recipients had to dig through to unearth a coffin. Inside the coffin was one of the seven cursed zombies, complete with background information and name.
The film company Laika used 3D printers to generate all of the different faces needed for the characters. Except the zombies, which had mechanical faces with silicone skins.
A vending machine is shown to sell "Cujohs", a direct reference to Cujo (1983). It even has a dog as a logo.