Unstoppable Force

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

It is represented by a silver six-pointed star with a purple MJOLNIR helmet with outward-pointing spikes.

Trivia

 * 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.
 * The name of this and the Immovable Object medal are a reference to the physics question/joke: "What happens when an immovable object meets an unstoppable force?"