Box Labeled "Danger: Void Rat Inside"

SS Companion



The Box Labeled "Danger: Void Rat Inside" teaches you how to summon a Void-Scarred Rat, a rat companion.

Source
This item can drop from Kelsey's Corrupted Chest in the Vision of Stormwind.

Pet Journal
A recent debate has risen up about whether Void-Scarred rats are better or worse than plagued rats.