Gears of War 3 will offer a novelty big-head mode, and those in the game's multiplayer beta saw it in action yesterday. In addition to quadrupling the dome size, COG and Locust will speak in higher pitched voices. This should make headshots a lot sillier.
Xbox 360 Games - E3 2011 - Gears of War 3
Gears Of War 3 Big Head Mode Revealed — It Also Has Squeaky Voices[G4TV]