Ninny

The Ninnies were "lithe, brutal-looking" Martians with purple skin and rugbyball-shaped heads. They had large lilac and green eyes.

A few Ninnies came to Putney Common and bought a sausage factory. The factory was secretly a front for a project to splice alien remains with kidnapped humans to create more Ninnies. Iris Wildthyme learned of this scheme, created a de-ninnificator, and defeated the Ninnies with the help of Dodie Golightly. (PROSE: The Ninnies on Putney Common)

Behind the scenes
The Ninnies originate from Paul Magrs' storybook The Ninnies, which was published by Obverse Books.