Professor Gracklebone is a customer at the Arceuus Library. He seeks certain texts within the library, and will ask the player to retrieve them. He will give players a book of arcane knowledge once a text is turned in, in addition to 2.5% favour.
Players who speak to him will learn that he teaches magic at the Tree Gnome Stronghold, and visited Great Kourend to learn its foreign magicks.
Professor Gracklebone is the solution to the medium cipher clue: QSPGFTTPS HSBDLMFCPOF. The answer to his challenge question: How many round tables can be found on this floor of the library? is 9.