'Deadpool' director Tim Miller is working on 'X-Men' spin-off movie 'Kitty Pryde'.

A solo film about the feisty mutant, also known as Shadowcat, is currently in development at 20th Century Fox, sources have told Collider.

Kitty Pryde was last seen played by Ellen Page in 'X-Men: Days Of Future Past' and has up to now been a side-kick character in the 'X-Men' movies and Marvel comics.

Kitty's powers include a phasing ability with objects and people, as well as disrupting electrical fields and levitation.

The project is still in the early stages, with director Miller also busy helming a new 'Terminator' film and producing the upcoming 'Sonic the Hedgehog' movie.

But if the 'Kitty Pryde' film does make it to the big screen it will add pace to the growing trend for female-led superhero motion pictures which is starting to emerge, with the likes of 'X-Men: Dark Phoenix' starring Sophie Turner.

The 'Kitty Pryde' project is not thought to be near the casting stages yet, and as a spin-off movie, with a possible origins plotline, it may be that Ellen - who has taken the role on twice, including in 'X-Men: The Last Stand' - does not return to play the character.

'A History of Violence' actress Sumela Kay played Kitty in the original 'X-Men' movie, and the role was taken on by Inconceivable's Katie Stuart in 'X2' in 2003.