 The B'omarr were still in Jabba's Palace at the time it appears in Return of the Jedi, and indeed, as C-3PO enters Jabba's palace, a spiderwalker can be seen.The monks inhabit the lower part of the palace and allow the various smugglers and crime lords like Jabba to use the upper levels, as long as they add another section to the lower levels for use by the B'omarr.When the current ruler of the upper levels is deposed they drive out the stragglers and add the brains of those who do not leave to their order.