Stupid Horse

The Stupid Horse exists to stop Sally from stealing, and it only appears when she does. It belongs to The Hotel and spawns in the same room where Sally appears, either inside a container or on top of a table. Hold it out, and Sally takes the horse, deals no damage and sits on the floor playing with it for fifteen seconds before despawning as usual. The wiki also lists it under the name Sally's Toy.

What it looks like

The item is the silhouette of a 3D horse model outlined in purple, matching the design of the joke entity of the same name. That entity, the STUPID HORSE, is available only in Stream Integration and Chaos Mode, and the wiki says the item was clearly designed to bring the joke into the base game. The page notes that this entity notably annoys the DOORS YouTuber Cheddar Balls.

In multiplayer

When several players are in the room, Sally always runs toward whoever is holding the horse, regardless of who is closest. That makes the player with the toy the target, so the item works as a deliberate decoy as well as protection. The item is minor, stacks to one and was first shown in the Archives update.