It is as I feared -- the toxin is simply too weak for such a powerful creature.$b$bIf we are to create a toxin of high enough potency, you must venture to the bottom of the Temple of Atal'Hakkar, unlock the secrets of the altar and recover a putrid vine from the guardian there.  The temple is dangerous, and it would behoove you to bring friends.$b$bReturn to me when this is done.