Grail Quest is a series of gamebooks by J. H. Brennan. The books are illustrated by John Higgins (I).
The series is (usually) set in King Arthur's realm of Avalon, and follows the adventures of a young hero named Pip. Pip is often called upon by Merlin to right wrongs and save the realm from evil.
The series is light in tone and does not take itself seriously, often spoofing the fantasy genre and inserting a lot of pure slapstick humor or nonsensical elements in order to make the book a fun read. Occasionally there is more serious drama, but this is usually reserved for very special moments.