Brahmin Herd (Fallout)

Brahmin Herd is a special encounter in Fallout.

Overview
For this encounter, you come across a herd of six wild brahmin. They say "Moo!" or "Moo, I say!" without attacking the player and leave as if nothing had happened.

This special encounter is very hard to find and rarer than others, even with 10 Luck.

Behind the scenes

 * This encounter was inspired by a prank Timothy Cain used to play in the MUD Darker Realms, where he would teleport cows who had similar dialogue into a friend's work room. A similar joke is present in Blizzard's Diablo, when played with the Hellfire add-on.
 * Ed in Vault City says that he swears he could hear his brahmin say "Moo, I say!"