BOB

The BOB is a special type of enemy encountered in Halo: Reach. The BOBs usually take the form of yellow/gold-armored Sangheili Rangers. In the level ONI: Sword Base, BOBs take the form of a white-armored Elite with randomly generated armor, ranging from Minor to Field Marshall. These white-armored BOBs always dual-wield Plasma Rifles, regardless of rank. The yellow/gold-armored Ranger class BOBs, on the other hand, have been seen with Plasma Rifles, Plasma Repeaters, Concussion Rifles, Fuel Rod Guns, and even Energy Swords. The BOBs' energy shields have the same strength of an Elite General.

Description
Each BOB has a set time limit before it vanishes. For some BOBs, this time frame begins as soon as it is alerted to the player's presence. For others, the countdown begins once the player enters a certain area, thus it is possible for the player to miss the BOB entirely if it is not spotted. When the limit is reached, the BOB activates Active Camouflage and disappears completely.

Killing one of the BOB's will reward the player the "Seek and Destroy" medal. However, the medal can only be viewed on Bungie.net. In the post-game carnage report, the BOB is referred to as a "Elite light vehicle". On Bungie.net, their description is simply "Wipe them out."

The name "BOB" is a reference to Bungie's Marathon video game series. All human characters in the series, besides the player, are known as "BOBs". "BOB" is an acronym for "Born on Board", a reference to the characters having lived their entire lives onboard the titular colony ship.

BOBs are considered Easter Eggs, and thus have no canonical explanation in the storyline.

Winter Contingency

 * Weapon: Plasma repeater, Concussion rifle (on Legendary)
 * Rally Point Alpha:
 * While looking for 3 Charlie, the player will find 3 different buildings, the first building is the one where the player cannot find 3 Charlie, it has 3 spawn point for the BOB, one for every small section of the place.
 * The second building is located next to the river, it has 2 spawn points, one inside a basement with a broken wall and another next to the dead marines inside the building.
 * The third building is located near the broken bridge, it has 2 spawn points, one on the dark building, next to the window, the other one is next to the dead civilians.

ONI: Sword Base

 * Weapon: Dual-wielding Plasma rifle
 * Rally Point Bravo:
 * Just before fighting the Hunters inside the base's garage, a random armored white Elite can be seen on the courtyard.
 * Rally Point Charlie:
 * Inside the base, on the fourth floor, a random armored White Elite can be found.

Nightfall

 * Weapon: Plasma rifle
 * Mission start:
 * A golden Elite ranger can be seen on the broken bridge where the dead militia is.
 * Rally Point Alpha:
 * One can be found on top of the smallest building on the settlement.
 * Rally Point Bravo:
 * One spawns next to dead militia soldiers on the bridge. After it spawns it will go to a rooftop and will stay there.

Tip of the Spear

 * Weapon: Concussion rifle (first one), Fuel Rod Gun (Last three)
 * Mission start:
 * When heading to the first AA Cannon One can be found on the hill at the far left of the gun.
 * Rally Point Bravo:
 * One in front the crash site in the rocks.
 * One on a cave at the far left of the crash site.
 * One at the place where Bravo Generator is located on Invasion.

Long Night of Solace

 * Weapon: Plasma rifle
 * Mission start:
 * A pod with a BOB inside can land on 3 random places. The first one is in front of the facility, over the small hill, the second one in almost the same place, but it will land near the human barriers, and the third one will land next to the platform where the Wraith can be found.
 * Rally Point Bravo:
 * One can be found on the main controls of the corvette on the bridge.
 * One can be found when the player returns to the Hangar to defend the Pelican, on the top floor.

Exodus

 * Weapon: Banshee
 * Rally Point Alpha
 * When heading to the extraction point, a BOB piloting a Banshee will spawn near the docks and fly over the highest bridge.
 * Rally Point Bravo:
 * Just when the chapter starts, a BOB piloting a Banshee will spawn at the far right of the tower and will fly over the extraction point.
 * Another one can be found while clearing the beach at the end of the mission if the player is near the bridge.

New Alexandria

 * Weapon: Banshee
 * Mission Start:
 * If the first objective is not Club Errera, at exactly 5 minutes into the game a BOB-piloting Banshee can spawn on 5 random locations:
 * Nomolos tower, heading to the sea.
 * Nomolos tower heading to the glassed area.
 * From the glassed area to Club Errera.
 * Near the Hospital heading to the sea.
 * Near the Hospital heading to the glassed area.

The Package

 * Weapon: Concussion rifle (First Three), Banshee (last one)
 * Rally Point Alpha:
 * One can be found on the courtyard.
 * One can be found inside the base atrium, next to the Datapad.
 * Rally Point Bravo:
 * On the final wave, a Phantom will drop one near the cliff.

The Pillar of Autumn

 * Weapon: Concussion rifle
 * Rally Point Alpha:
 * One will spawn at the far right of the area where a large battle is being fought under the UNSC Commonwealth, and is almost impossible to sprint where it is without getting it to despawn. The Spartan Laser found as you enter the area should be used.
 * One will spawn in the garage on the next zone, exactly where the Scorpion spawns in Invasion.

Lone Wolf

 * Weapon: Energy Sword
 * Mission Start:
 * If the player manages to survive until the generals start spawning, a BOB will spawn on the open area at the left of the mission start.

Trivia

 * There are 7 spawn points for BOBs on the level Winter Contingency, referencing Bungie's favourite number.
 * On page 384 of the Halo: Reach Official Strategy Guide, there is a list of enemy point values. In this list, there is an enemy called a "Daily Challenge Elite", which has the same point value of a BOB (200 on Normal difficulty).
 * There are Daily Challenges awarded for killing a Golden Ranger-class Elite, including "What's Up Bob?" and "If It Bleeds..."
 * Banshee BOBs have no pilot, and do not award a Seek and Destroy medal, but they are considered BOBs for the daily challenge "Golden Tree City".
 * The page about Sangheili Ranger in the Halo: The Essential Visual Guide has a BOB as its profile image beside the main summary.