Freezing Jackal
From Halopedia, the Halo wiki
Play Outskirts on Legendary until you get to sniper alley. Get a sniper rifle ( or beam rifle. which ever you prefer) then shoot the jackal that walks into the open in the body. Usually he freezes and draws a plasma pistol but very rarely dies frozen in mid air if you shoot its head. Occasionally he will shoot you with the plasma pistol while he is frozen.
