There's some kind of smart brain bug in the back of the cave. It's in charge of all of the silithid down there.
My ice cream is melting! How am I supposed to launch my ice cream empire, and save my inventory, if that thing's in there?!
("Slay the Hive Controller for the future prosperity of the Ice Cream Empire!")
Rewards
You will receive: 1 15
Progress
<Name>! Get down there and kill that thing!
Completion
Outstanding! Nothing can stop us from being the greatest purveyors of ice cream in all of Azeroth!
Notes
Pick up Freezing the Pipes before jumping in. After freezing the four pipes, continue to the southwest to take out the Hive Controller, a level 42 silithid with 2642 health.