The Screams of Brahmin (quest)

The Screams of Brahmin is an unmarked quest in Fallout: New Vegas.

Detailed walkthrough
During conversations with certain Novac townsfolk, such as Jeannie May Crawford and No-bark Noonan, the Courier can learn of mysterious attacks at the nearby brahmin ranch. These conversations merely give more information, but are not required for the quest. In fact, the only way to initiate the quest is to speak to the ranch owner, Dusty McBride.

The ranch is located in Novac, to the south of Novac house or west of the Dino Dee-lite Motel. You can also find it to the west, on the left of the road which leads into the hills behind the town. Dusty McBride can be found inside the adjacent McBride house. He explains the situation, and advises the Courier to wait near the brahmin pen at midnight for the attacker, which is also mentioned in the note that he provides.

The attacker will appear as soon as the Courier exits the house. The assailant is a nightkin, who waits near the large boulder behind the house, hidden with a Stealth Boy. Targeting the area with V.A.T.S. will reveal his location. He will ignore the Courier, and at midnight will move to the pen and begin killing brahmin. There is no need to wait for this event; he can be attacked at any time.

The nightkin will remain hidden most of the time. He will only reveal himself while he is about to shoot at the Brahmin. The nightkin must be killed in order to advance. He is non-hostile to the player until attacked, but attacking and killing him has no effect on Karma. A holotape entitled The Screams of Brahmin can be found on its inventory, which goes some way to explain the attacks. After killing the nightkin, return to Dusty and speak to him again to complete the quest.

Upon completion, Dusty will give the Courier 75 caps and access to his freezer, which contains 9 or 10 brahmin steaks. Additionally, the Courier will gain Novac fame sufficient for Accepted status without any prior contact, and positive Karma.

Behind the scenes
No-bark describes the nightkin as an "invisible chupacabra." A chupacabra is a cryptid whose legend is most commonly known in Central America.