Serpentshrine Cavern Easter Egg in Patch 9.2 - Find The Lurker Below's Soul in Maldraxxus

wowhead.com:

A new easter egg has been discovered on the Patch 9.2 PTR, where we find the soul of the fishing boss in Serpentshrine Cavern, The Lurker Below! One of the more elusive rares in Patch 9.2 is Hirukon, an aurelid that needs a special lure to be fished out of his underwater spot. To be able to fish this rare and obtain its Deepstar Polyp mount, you must go on a fishing journey that starts with the Strange Goop, an item fished from the lake Hirukon can be found at in Zereth Mortis. The Strange Goop mentions that someone with knowledge of deep sea creatures might be able to fashion a special lure to fish the rare. For more information on how to fish Hirukon, check the NPC page comments or our Zereth Mortis Rares Guide. The being mentioned in the Strange Goop's item is none other than Baroness Vashj, a Naga in life who was indeed adept with deep sea creatures. She can be found all the way south of Maldraxxus, fishing at a secluded lake accessed by going through a cave in Plague's Watch. As you talk with Baroness Vashj to discuss what to do with the Strange Goop, she does offer to help, but at the same time mentions we're disturbing her favorite fishing spot in Maldraxxus, and to not disturb a certain soul.

As of note, unlike previous chats involve Baroness Vashj, this dialogue is the same whether your character has done the Serpentshrine Cavern raid or not. Once you look at the lake, you might see a fin sticking out from the water, but the real treat is when you swim underwater: