Unstoppable Force

Unstoppable Force is a multiplayer medal in Halo: Reach awarded when a player achieves 15 kills in a row as the Juggernaut without dying when playing a Juggernaut game variant.

There was a similarly named medal in Halo 3, Unstoppable, awarded for a 10 kill streak as the Juggernaut. In Halo: Reach that medal was renamed Immovable Object.