Flying Half-Jaw
From Halopedia, the Halo wiki
In Halo 2, on The Oracle, when you first encounter the Flood, it is possible to make Rtas 'Vadum or "Half Jaw" fly in the air anytime he is attacked by an Infection form.
Walkthrough
First and foremost, it is recommended to do this on Easy. To do this, you must make him your enemy at the very beginning of the level. This is simply done by killing everyone on your team (both Elites and Grunts), who are with you at the start of the level. Defend yourself from the invincible Elite Commander until the Heretic Leader's hologram appears. At this point, Rtas 'Vadum will become an ally again, talk to the hologram, and fight the Flood that soon attack.
Whenever an infection form jumps onto him, he will attempt to kill or "pop" it using his Energy Sword. After enough infection forms attack him, and he loses his shields, he will fly through the air, seemingly floating.