Scorpion emblems

The Scorpion emblems are various pictures that are visible on the front left tread of the Scorpion tank, which varies depending on whether the player is playing campaign or multiplayer.

Description
The picture varies between a hand, a lightning bolt, a chess knight, and two circle glyphs. The chess knight appears on the Scorpion's tread in the Halo 2 game manual, while the chess knight is visible in Halo 3 on either side of the Scorpion.