Manticore in Steve Jackson's Sorcery
I remember the old Fighting Fantasy gamebook series Sorcery.The first book the Shamutanti hills had a Manticore on the cover.The Manticore's lair was the final difficult obstacle to overcome in completing the book.
Original Cover
http://www.gamebooks.org/gallery/sorc1.jpg
Recent Reprint Cover
http://www.fightingfantasygamebooks.com/images/covers/shamutanti.jpg