The Sumatran Rat-Monkey (Simian raticus) is a creature created by director Peter Jackson for his demented 1992 zombie horror comedy Braindead (known in the US as Dead Alive). In the film's prologue, we learn that this nasty beast lives on Skull Island - the fictitious location of the 1933 classic film King Kong.
According to the film's lore, the Sumatran Rat Monkey is the result of small tree monkeys having been raped by giant plague rats that swam ashore from a sinking ship.
The monkey looks more like a rat than an ape, and its most notable features remain its wide, black eyes and its two long front teeth. It is nearly hairless and its skin colour is a brownish gray. Its Nosferatu-like fingers are essentially claws and it has a surprisingly large amount of strength - easily ripping apart a monkey his same size in the zoo sequence.
It is brought to life in a jerky stop motion style, as a homage to veteran effects master Ray Harryhausen. In the sequence before the credits of the film, a hunter and his assistant evade the natives of the island and carry the monkey away for delivery at the Wellington zoo. The ape, however, breaks out of its cage and bites the hunter - leaving the assistant to hack off all of his body appendages because the simian carries a virus that turns its victims into flesh eating zombies.