Goofy yell tribute
From Halopedia, the Halo wiki
The Super Mario Tribute is a Mario-like laugh reportedly heard in the Halo 2 Campaign level High Charity, as well as in Valhalla and High Ground in the Halo 3 Beta
On High Charity, the player would have to climb onto a gravity lift near the end of the level. The player would activate a switch, wait for the lift to rise a bit, then slip underneath it. The game would detect the fact that the player was not in reach of the lift, and would lower the lift onto the player's head. The player would then occasionally hear the Mario Tribute laugh/scream. The laugh can only be heard in single-player or Xbox Live; Co-op has not yet been tested.
In the Beta, a player played on Valhalla with 300% speed and 50% gravity. The laugh was heard when he jumped a series of rocks leading out of the map. After that, the player leaped into the water and died, hearing a laugh/scream sounding like Mario. Also in the Beta on High Ground, the laugh was heard at the end of the match.[1]
Speculations
- It is possible that the laugh can be heard in other games/levels in the Halo Universe; it has been heard once right after getting the Grunt Birthday Party Skull on normal.
- The laugh has no connection to the Mario series; it is simply assumed by fans to be a tribute.