1 of 8
A new book, illustrated by Rob Steen, features 35 different characters invented by comic Ricky Gervais.

2 of 8
Gervais says he has always been interested in zoology, which prompted the idea for the book - he went to university to study biology but changed to a philosophy course.

3 of 8
"I've been trying to do it (the book) for about six years, but nobody answered the door until I knocked on it with four Baftas", says Gervais, who won the awards for The Office.

4 of 8
This creature, a hemel sprot, "rushes across the guddle deserts on its wobble pod", according to Gervais.

5 of 8
Illustrator Rob Steen's artwork was created using traditional methods and computer colouring.

6 of 8
The mernimbler is actually very cute-looking until stroked by an adult, when it turns into this monster.

7 of 8
The mernimbler looks even more frightening when produced in full colour.

8 of 8
The sprine bloat-trunker emerges from a sewer and is then recycled. The book is published by Faber and Faber on 7 October.