Beowulf

ONI Artificial Intelligence construct. Beowulf was the attaché to Admiral Micheal Stanforth and the UNSC navy. He was present during the Spartans original briefing about the Covenant.

He was later assigned to guard the UNSC personnel and planning database. He knew Cortana well, and knew that she was trouble. When she would try to get into the system, he would block her enterance.

He was thorough, methodical, and paranoid. However, compared to Cortana's code cracking skills, he might as well be an accounting program. He was incapable of learning because he was a "dumb" AI.

His hologram form was that of a man wearing a hooded cloak.

Also, though not proven, Beowulf was believed to be aboard the Pillar of Autumn as the second AI. Though not proven, it is listed as BW, possibly Beowulf

Trivia

 * Beowulf is also an Old English epic about a warrior of the same name. The warrior lived sometime between the 3rd century BC and the 17th century AD in what is now called Scandinavia. He is best known for the vowels in his name because at the time the manuscript was supposedly written, vowels hadn't yet been discovered.
 * The great Beowulf scholar J. R. R. Tolkien noted that the name Beowulf almost certainly means bee-wolf in Old English. The name Beowulf is therefore a kenning for "bear" due to a bear's love of honey and to the similarity and not-so-distant kinship between ursines and canines.