The thunder shall bring forth the pain! – When thrown, the grenade has very little arc and stays low to the ground. It behaves like a lobbed rubberized grenade at first but each bounce has a detonation. After several bounces or touching an enemy, it explodes like a MIRV grenade.
The name of the grenade is a reference to Operation Rolling Thunder, a massive bombing campaign conducted by the USA during the Vietnam War.
A SHiFT code that unlocks a single Rolling Thunder is included in the Diamond Plate Loot Chest. The caption on the item's card reads "If you use this thing indoors, it will be (A) awesome and (B) the last thing you ever do."