Approaching the cattle pen will uncloak a nightkin selling "wind-brahmin", which are the tumbleweeds that are littering the pen. The origin of this nightkin is completely unknown. It has no backround and no past affiliation with the character and/or any other of the in-game NPC's. If you ask the charge, he will demand all of your caps. If you state he is crazy, he will reply with: "Crazy with low prices on wind-brahmin". Whether or not the Courier has 10 caps or 10 million caps, that is considered the "low-price" of tumble weeds, or "wind-brahmin". Originally, if you agree without asking, he'll give you a Stealth Boy. But with the game patch released July 7–8, 2011, the nightkin will no longer give you a Stealth Boy if you agree without asking, and will take all of your caps instead. If you refuse, he'll become hostile. A Stealth Boy can be pickpocketed from the nightkin, or will be on his corpse after he is killed. Further interactions (insinuating that the tumbleweeds are not in fact "doggies") results in the nightkin becoming hostile towards the player. If a wind-brahmin is purchased, the nightkin can then be killed to collect the lost caps. Killing and/or any other form of interaction with the nightkin does not affect Karma. It should also be noted that just in front of the pen is a dead wastelander.
The nightkin in the cattle pen will not be visible because he will be wearing a Stealth Boy. When you get near him, he will deactivate his Stealth Boy and he will open the dialogue with you.
If you turn the nightkin hostile and lead it to Jacobstown, Marcus and the other mutants there will become hostile as well.
The tumbleweeds in the northwest corner of the pen seem to be attracted to that point. If rolled away from the pen, they will slowly be attracted back. This is due to the direction of the wind, and if lifted over the fence they will continue on west.
There appears to be one tumbleweed near the north corner of the pen which cannot be kicked around, and is not attracted to the northwest corner of the pen like the others. Also, when you try to push it, your footsteps sound as if you are stepping on a metal floor.
Another two tumbleweeds can be found inside the shack, one on the sofa and the other on a bed.
East of the farm is the mercenary camp with a group of heavily armed (and hostile) mercenaries. One of them is equipped with the unique YCS/186. This camp shares a spawn point with the aliens described below. If you have the Wild Wasteland trait, you cannot get this unique weapon. See next note for details.
If you have the Wild Wasteland trait activated, and you travel east from Brooks Tumbleweed Ranch, you will get the "Hovering Anomaly." What looked like a mercenary campground is actually an extraterrestrial landing zone, complete with spacecraft, and three aliens. The alien captain is equipped with the unique alien blaster.
xbox360pcps3 If you have spoken to the nightkin that is selling the tumbleweeds, and then decide to reload the save, he will not appear. Exiting the game and going to the main menu, or restarting your game will fix this, though this will lead him to spawning wherever you loaded (maybe on the other side of the map). This may also lead to him reappearing every time you restart. Upon spawning, he may become hostile to those around you (leaving you alone) and will start killing them. This could potentially be used to assassinate people of interest. It is also possible that he might appear later on, as if he followed you, to somewhere random.[verified]
xbox360ps3 If you kill the nightkin and come back a few days later, upon entering the pen you will hear the nightkin coming out of stealth but nothing will appear anywhere.[verified]
xbox360 When initiating dialog, if you accept the offer without asking how much, he will give you the Stealth Boy without taking any caps.[verified]