This quest was marked obsolete by Blizzard and cannot be obtained or completed.
Gather Un'Goro Slime Samples from any of the slimes in Un'Goro Crater. Then, using the Testing Equipment next to Chemist Fuely in Undercity, see which of your samples are the most pure. Bring 5 of the Pure Un'Goro Samples you find to Chemist Fuely.
Truly amazing, <name>. This Un'Goro Crater is holding many more secrets than I expected. I wonder what else we will discover as we test further.
Simply amazing... look at the purity of these samples. Hmm, I wonder what it could mean. They seem to be elemental in nature, but... something more. They remind me of... of the Old Gods. We've found traces of them throughout Azeroth, and now I wonder if these creatures aren't related to them somehow.