How do you get the mission to get into bartleby in wizard101?

one way to enter his mouth is first do the quest where Merle Ambrose tells you to defeat Foulgaze and Nighthshade then you can enter Nightside talk to Dworgyn in the Death School (in Nightside) then Merle tell you to go to Krokotopia to stop Malistaire getting the Order Of The Fang so first you talk to Bartleby and he tells you to go to the teleporter inside of him (The World Tree) ;D.