Decanus Severus

Decanus Severus is found in Cottonwood Cove. He is part of a free form quest in which the player may trade NCR Dog Tags to him for munition or victuals (after passing a Barter check with Phoenix who pays 10 caps per tag if the check is not passed).

Trade Items
Weapons:

25 Dog Tags -> 9mm Submachine Gun

Armor:

20 Dog Tags -> Leather Armor

25 Dog Tags -> Leather Armor, Reinforced

Explosives:

3 Dog Tags -> Frag Grenade

3 Dog Tags -> Dynamite

[Ammo and Food Supplies are of more negligible value, though for the great Caesar's Legion Fame, trade with Aurelius alone.]

Infinite experience and fame glitch
There is a glitch even in patched version which allows player to get infinite experience and Legion fame. In dialog choose the following: Reward: +50 exp and Legion fame. Could be repeated infinitely.
 * I have some questions.
 * Do you see much action against the NCR?
 * That's all for now.
 * I can show you how to disarm NCR's mines.
 * [Explosives 50] The trick is to rush the mine and press the blinking red light.

Behind the scenes
In Latin, decanus implies something "of ten". Decurion was a lesser rank in the ancient Roman military. Severus may be a reference to Septimius Severus, who was a Roman Emperor from 193-211.

Appearances
appears in Fallout: New Vegas.