Brahmin or Brahma are mutated cattle with two heads. In the real world, "Brahmin" is the priestly caste of India, one of 4 such castes. When the bombs fell, cows mutated and grew two heads, and were given the name brahmin. They also have 8 stomach compartments, twice as many as normal cows.
The brahmin are a toasty brown and quite hardy, as they are used as pack-animals as well as for food and farming purposes. They attack by head-butting or trying to gore someone with their horns, so brahmin-tippers beware! For some reason, only the left-most brahmin head has horns (in Fallout 3 they have horns on both heads).
Though harder to kill with bullets than people, one dart from the dart gun kills a brahmin. NPCs sometimes tell the player character that occasionally, a brahmin is born with a single head - essentially, a regular cow. Ironically, these single-headed brahmin are referred to as "mutated" brahmin.
All brahmin for some reason take less damage if you shoot them in the head than they do if you shoot them anywhere else.
"Mad brahmin" are believed to be either a brahmin with a pre-War disease known as "Mad Cow Disease", or simply a brahmin that has suffered brain degeneration to the point of hostility. Little is known about the condition, or why brahmin would become aggressive. They are sometimes sighted among inexplicably rotting corpses of other brahmin, suggesting some form of disease in the herd. Mad brahmin are aggressively hostile except to those with the Animal Friend perk. Though mad brahmin may be hostile, they are not deadly. Mad brahmin can be outrun, as well as being tipped and beaten with choice melee weapons.
- If killed, they give 1 xp and you get brahmin steak from the corpse.
- Regular brahmin (i.e. not pack brahmin) can be pushed over by crouching next to them and pressing the action button (only works if weapon is holstered).
- If you have the Animal Friend perk, mad brahmin are not hostile, and can also be tipped over.
Brahmin serve a vital environmental niche in Fallout -- they form the foundation of survival for many species; most notably, humans. They also form the backbone of the NCR economy and of the New Reno "NCR brahmin rustling" economy. Brahmin can pull carts, old cars, plows, and dead bodies. Brahmin can be driven into herds then used as stampedes on rival tribal villages. Brahmin hair can be woven into bags and ropes. Brahmin sinew can be used for bowstrings or thread for stitching. Brahmin droppings are a great for fertilizer and fuel for campfires- the fumes from their feces are also used to synthesize Jet. Brahmin meat is delicious - if only when compared to other sources of food. Brahmin are a source of milk that is like modern day milk, yet strangely different, it has been said to help heal radiation poisoning. Brahmin bones can be used as clubs, knives, arrowheads, eating utensils, hoes, or even dice, and their skulls look really scary dotted all over the desert landscape. Their hide can be used to make tents (or teepees), clothing, belts, saddle bags, shoes, leather armor, leather jackets, or a bizarre brahmin-looking disguise.
There are domesticated brahmin and wild brahmin. Wild brahmin can forage for themselves, and can be found across the wastes, gathered into small herds, wandering here and there, munching on the dirty weeds scattered throughout the desert. Fortunately for the ecology of the wasteland (and the survival of their species), brahmin can go for long periods of time without water - they don't need much to survive. They have a strong sense of smell, and they don't hesitate to stomp over any wasteland predator that threatens them or their calves - with strong exception to the deathclaws, which prey upon them among countless other, less powerful creatures.
Appearances in games
The brahmin appear in all Fallout games.
One also appears as an Easter egg in Arcanum: Of Steamworks and Magick Obscura, shown in a freak show and described as coming from "a far away wasteland".
In Fallout 3, you can go "brahmin-tipping" by crouching and activating any brahmin that isn't attacking you. There's no activation symbol, like when you target a door and it says "open door", but you push them over all the same. It uses a unique animation seen at no other point in the game, and the brahmin moos and turns into a ragdoll for a few seconds. To do this, press the "activate" button. In Fallout: New Vegas, Brahmin tipping counts towards the Knocked Up ingame challenge.
This is an Easter egg, likely a reference to a quote from Tandi in Fallout, where she describes what there is to do in Shady Sands. She says that "brahmin-tipping gets old real quick." In Fallout 2, if you use the move function on a brahmin, it will fall over. Scavenger brahmin can't be tipped.
If you tip a Brahmin while you have an "unarmed" style weapon equipped, during the tipping animation your character will be wearing that weapon. This also works with the Shishkebab, because the oven mitt used to hold the weapon stays on the user's hand, producing a humorous effect.
In Fallout, brahmin would occasionally be heard to exclaim "Moo, I say!" Additionally, Moira Brown's terminal refers to the brahmin language, raising the possibility that they are smarter than they appear. It is possible that brahmin actually say the word "moo" rather than mooing like cattle.
Brahmin-tipping also features as a special random encounter in Fallout Tactics.
Behind the scenes
The brahmin in all the Fallout games refer to the brahmin in Hindu culture. Their use in the Fallout games is likely a play on the reverence held for cows in Hindu culture. This has been seen as disrespectful to the Hindu culture, and use of the name brahmin was banned in India from Fallout 3.