Born during the Great Quake that shattered the Arena's western wing, Rubble Rumbler emerged from warriors who survived structural collapse by turning falling stone into weapons. These Birbs perfected their seismic techniques in Grave Gobbler's unstable cliffs, learning to channel tectonic energy through their talons. Now they symbolize how fundamental endurance transforms disaster into battlefield dominion.

Manifests kinetic energy absorbed from fractured arena stone, with seismic resonance detection guiding its movements. Can redirect tectonic pressure through its limbs and temporarily fuse with mineral structures for camouflage. While vulnerable during airborne assaults, its destructive potential scales with available geological mass in the battleground. Each step leaves pulverized stone in its wake.

Alters battleground dynamics by collapsing aerial approaches and ranged positions, forcing all combat into close-quarters terrain where Birbs' endurance prevails. Serves as living terrain-shaper that reconfigured arena layouts mid-match to disadvantage flying specialists.