Balloon Spider

The Balloon Spider is a giant spider-like monster made of balloons featured in the film Goosebumps 2: Haunted Halloween.

History
The Balloon Spider was originally an inanimate Halloween decoration made and owned by Mr. Chu. When Slappy the Dummy brought the spider to life using the Tesla Tower, it began scaring off pedestrians and trapping them in webbing. When Sonny Quinn, Sarah Quinn, and Sam Carter returned home with Haunted Halloween, they found their mother Kathy webbed to a tree. After Sarah loses the book to a bedsheet ghost, the spider snatches Kathy and brings her to Slappy at the Tesla Tower.

The spider reappears during Sarah's fight with Slappy, apparently destroying one of its legs when it tried to stab Sarah. After Sarah triumphed over Slappy, she began using Haunted Halloween to suck in the spider. It's unsuccessful at first until the book absorbed Slappy's magic from the Tesla Tower.

Trivia

 * The Balloon Spider's appearance in Haunted Halloween is a spiritual successor to the Giant Praying Mantis' role in the first Goosebumps film.
 * In the tie-in movie novel, it is described that if the spider were to have its balloons popped, dozens of tiny spiders would be released.
 * The spider also makes an appearance in Goosebumps HorrorTown where it's a collectible monster that can be seen during the Haunted Halloween event.