The Unloved

The Unloved are a collection of twelve hideous, living masks who desire to possess their wearer, passing on their characteristics onto them. They appear throughout the The Haunted Mask saga.

History
The history of The Unloved changes between stories; many details about their past has been contradicted.

The Haunted Mask
The Shopkeeper tells Carly Beth Caldwell that the masks in the back room are in fact actual faces that he made in a lab. The faces used to be beautiful and alive, but they became ugly as soon as they left the lab. He calls them The Unloved because nobody wants to see them. Sometimes people take the masks, and the masks find "a new home". The masks fuse onto their wearers faces and stay there unless they are removed by a symbol of love.

Goosebumps Official Collector's Caps Book
The first of the two Goosebumps Collector's Caps Books provides background information on the Shopkeeper.

Long ago, a handsome teenager lived on Maple Avenue. He was a good student, but he was failing chemistry because his chemistry teacher was very mean and refused to spend any time helping the boy. The boy took matters in his own hands when he crept into the chemistry lab late one night to practice a few experiments of his own. The boy accidentally mixed the wrong chemicals in his test tube, and the tube exploded all over him. Instead of burning his face, the chemicals rapidly aged the boy's face. Overnight, he became an old man with a thin mustache and a pinched face. The boy became desperate to get his former appearance back, so he started experimenting with making masks. As he got older, he eventually becomes the Shopkeeper.

Goosebumps Wanted: The Haunted Mask
This book retcons the backstory given in The Haunted Mask and in the first Goosebumps Official Collector's Caps Book. In this book, the masks are referred to as "The Unwanted."

William, owner of William's Mask Emporium, was approached by his brother one night and he carried a briefcase full of the Unloved masks. The "masks" are actually the preserved faces of the most hideous and deformed people in the world that are said to have the same evil properties if worn. William's brother forces the Haunted Mask onto William's face, and he leaves as William freaks out and trashes his house. In an attempt to remove the mask, William tugs at it until his own face comes off inside of the mask! William then ducks into a closet and throws the Unloved in a locked chest with him before dying.

Goosebumps 2: Haunted Halloween
An Ogre Mask-based off the Old Man Mask (from The Haunted Mask II) appears in the film Goosebumps 2: Haunted Halloween as a Goosebumps-themed Halloween mask brought to life by Slappy the Dummy. The mask immediately flies onto the face of Walter, the manager of Fred's Pharmacy, and transforms him into an Igor-esque ogre.

The mask remains on Walter's face until it gets removed towards the end of the film when it gets sucked into Haunted Halloween along with all the other monsters, returning Walter to normal in the process.