The "Killer Jokes of the Trixter" are booby-trapped books, that appear in Ultima VII Part Two and Ultima VIII. They are vastly different from any other book encountered. The books all read like this:
KILLER JOKES
by Trixter
Welcome reader and learn the age old art of practical jokes. I, Trixter have studied long and hard from the tomes of the ancient masters to achieve the knowledge and wisdom that I may now impart on you, the novice.
Chapter One:
Exploding Books
(Heh, heh...)
Afterwards, they all will explode and, in the worst case, cause death to the reader.