Dual Melee

In Halo 1 and 2, when wielding a Plasma Pistol, press the X and B buttons repeatedly. This will cause the Pistol to produce its normal melee animation (where the Chief uses his fist), and then another, where he hits with the gun itself. This can be hard to see at first, since the animations occasionally "go through" one another, but it is still there, nonetheless.

It is unknown if this is a hidden animation left by Bungie, or a bizarre glitch of some sort.