Grenade slide
From Halopedia, the Halo wiki
The Grenade Slide is an animation error present in Halo: Combat Evolved. The glitch causes a player's legs to stop animating as they throw a grenade. The glitch is only visible in Co-op or Multiplayer, as players cannot see their own legs in-game.
Instructions
To observe the glitch, two players (Person A and Person B) must cooperate.
The two players should find a room that they can run around in. Person A should obtain grenades (any type), while Person B should step back and watch Person A. Person A should start running, and as they run, they should throw a grenade. Person B will see Person A's legs stop moving, making A appear to slide along the ground. When the throw is finished, Person A's legs will return to normal.
This glitch can also be seen with the deathcam, typically in games involving infinite grenades. If the player is killed amidst opponents, the opponent may choose to throw a grenade near the dead player's location.
Explanation
When Bungie made the animation for throwing a grenade, they did not animate the lower half of the body; they forgot to code the animation to only include the arms, so when a Spartan model throws a grenade, its legs revert to a standing position. A similar glitch occurs when players throw grenades from the passenger seat of a Warthog or Scorpion, with the player standing up inside the vehicle to throw the grenade.
