Robbie the Rabbit is an anthropomorphic rabbit doll that has made appearances in many of the Silent Hill games. In some of his appearances, his mouth is covered with blood. For the most part, his appearance seems to serve little more than to provide an ambiguous level of unease to the player, due to the odd nature of his existence within the world of Silent Hill, his bright colors compared to the rust brown and dark red of everything else, and his recurring cameos.
Robbie's character could be seen either as an in-joke, a homage to the many horror films that depict bloodied rabbits as nightmarish killers, or it could even be an element of the town itself. An allusion to Silent Hill's dark sense of humor would be fitting as many of the game's plots involve the town's children in some aspect. It's possible he is simply there as a plot device to help tie each game together in a small, yet memorable way.
Silent Hill 3
Robbie's first appearance is in Silent Hill 3, where he is revealed to be a mascot for the Lakeside Amusement Park. Large models, possibly costumes, of Robbie can be found slumped in various areas of the park as if dead. It isn't quite clear whether or not there is a person, alive or dead, inside, or if the mascot is sentient. Robbie's 'corpse' can be seen many times while exploring the amusement park and he can also be seen as a doll in the souvenir store. Examining the tourist information scattered throughout the amusement park reveals that Robbie is one of its four animal mascots, along with Kathy the Kitty, Huey the Horse and Dawn the Duck. Heather Mason can also unlock a Robbie t-shirt to wear. He also appears as the icon for the game's save file on a PlayStation 2 memory card, which shows him running, or, perhaps more appropriately, chasing.
Silent Hill 4: The Room
In Silent Hill 4: The Room, a Robbie the Rabbit doll is sitting on a bed belonging to Eileen Galvin. While he isn't seen actually moving, he does change posture once Eileen is rushed to the hospital. He is then turned toward the player, pointing at Henry Townshend with a menacing expression. A hot-air balloon of his head can also be seen outside of Henry's window, which, for unknown reasons, has its mouth bloodied. Cynthia Velasquez also has a tattoo of Robbie, only visible when she is wearing her alternate costume.
Silent Hill: The Arcade
In Silent Hill: The Arcade, Robbie is an enemy and he appears in groups at Lakeside Amusement Park. They have squeaky, high pitched laughs that they use before attacking the player. Because The Arcade takes place before Silent Hill 3, it can be assumed that The Arcade is the reason for the bloody costume corpses in Silent Hill 3. Robbie also appears in the UFO ending's credits, where he is seen playing an arcade game.
Silent Hill Homecoming
In Silent Hill Homecoming, he is once again a doll. Alex Shepherd is required to retrieve the doll, which is stated to be a toy belonging to his brother, Joshua. It is here he poses as an interactive obstacle; failure to pull him correctly from a bloody hole in the wall results in Alex's arm being severed. He makes a reappearance later as a key to opening a door. The doll is not the instigator of these events, however.
Silent Hill: The Escape
Robbie acts as a tutorial guide for the game.
Silent Hill: Revelation 3D
Director Michael J Bassett has confirmed on his blog that Robbie will make an appearance in Silent Hill: Revelation 3D, the sequel to the 2006 Silent Hill movie.
Interesting note
Robbie is very similar to Billy from the Saw franchise. Both Robbie and Billy are inanimate objects but are treated as any other character, and both are unsettling and are used to unease people. Also, both have very small roles in their respective franchises, but both are very iconic.