Wikipedia
Grailquest
GrailQuest is a series of gamebooks by J. H. Brennan. The books are illustrated by John Higgins. The stories follow the adventures of a young hero named Pip, who 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 slapstick humor or nonsensical elements.
The series is mostly set in King Arthur's realm of Avalon, although the fourth volume, Voyage of Terror, takes place almost entirely in ancient Greece, after Merlin's summoning spell goes wrong.
While there were eight total books published in the series, books seven and eight were never published in the United States.