From Halopedia, the Halo wiki
Juggernaut Spree is a multiplayer medal in Halo 3 and Halo: Reach awarded when any player kills five opponents in a row as the Juggernaut without dying in a Juggernaut game variant.
It is represented by a steel four-pointed star with a blue MJOLNIR helmet with outward-pointing spikes.
The Halo 3 version.
The remodeled version in Halo: Reach.