S4·E131 Rampage
Aired May 2, 2009
Synopsis
When Hibari opens his original hedgehog box weapon, the hedgehog starts to act drunk from the amount of flames from Hibari's Dying Will given to it. After accidentally poking Hibari's hand, the hedgehog becomes mentally shocked and goes out of control. It rapidly starts to grow, endangering all those around it. Meanwhile, Tsuna heads toward the lab with Spanner in tow.