"Ah right, sorry, new experiences. Allow me to tend to your wounds, you wouldn't mind if I examine the exposed anatomy and make the proper mental notes before my magic seals them up would you? Such fascinating insights into terrestrials...No? Very well then, perhaps some other time." R'Lyeh was morally ambiguous, it seems the pursuit of greater understanding transcended cultural norms. Even for S'Augwin standards. Then again, his friends were not quite S'Augwin and thus were subject to study. 

"So given the nature of the potion, I had tested on local animalcules mind you in micro-scale amounts. Now before I go into greater detail about the experimental set up and rationalizations, I'll skip my methods in favour of presenting the results. From a data point of 12 insubstantial creatures, arthropods common to the area I assume, the potion is of a polymorphic origin. That is to say appropriate scaling of dosing has created matter beyond the normal form, albeit unable to maintain the new form for very long. The polymorph lasted about 10 seconds given the minuscule amounts of potion I had tested with."

And from there, R'lyeh took a swig of water, examining the injured and injuries sustained in battle.

"All that being said, the potency of this alchemic mixture is evident and, appears to trend to polymorphize the test subjects into larger reptilian creatures. And as for our loot, I shall take this time to study the undead corpses here while we recuperate. Would you care for some internal organs or viscera? A Necromancer's touch should preserve the body from advance necrosis for a decent amount of time." The fish was all too excited, and had already began to cut into one of the fallen zombies.
Something about the potion seems to have something to do with reptiles.
Something about the potion seems to have something to do with immense power.