Tsang Wuqiong, the August Emperor of Jade, the Infinite King
Some sovereigns prefer a different sort of tax from their subjects - whether freely given, or taken by force.
Inside a mad scientists laboratory the PCs find a short creature with smooth, oily and whale like skin. The head is faceless and smooth also. But hundreds of white eyes on the PCs from the fat belly of this creature. The PCs are about to kill it as it speaks to them in a feeble but intelligent voice, asking them to pour the contents of a green vial on it. Will they do so? And if so, what will happen?