Sneaking up behind and activating a Brahmin will cause your character to push it over.

In Vault 87 is a Super Mutant that calls himself "Fawkes" locked in Isolation Room 05.

This is a reference to the comic-book V for Vendetta, where the main character (V) is originally a prisoner from "Room 5" at Larkhill Internment Camp. After escaping, V dons the infamous mask of Guy Fawkes, the real life British revolutionary known for the failed Gunpowder Plot in 1605.

Both V and Fawkes gain super strength and intellect after their experimentation, which is rare as most Super Mutants only gained super strength but suffered mental drawbacks (or even died), and in the case of V, most subjects did not survive the experiments.

Near the NN-03d SatCom array, a door can be found built into a rock; Upon opening it there is a wall with "Fuck You" written in green paint.

In the corner of the map, you can find a building called the Dunwich Building. This building is named after the H. P. Lovecraft story, The Dunwich Horror. The building also takes inspiration from other Lovecraft stories like the Cthulhu mythos.

"The Plunger Room of Death" is a small area unmarked on the Pip-Boy world map. It is located South of the Chryslus Building, and East of Farragut West Metro Station. The entrance is a door underneath an intact bridge. Inside are dozens of toilet plungers and bloody hand prints on the walls.

A small, playable text adventure called 'Reign of Grelock' can be accessed from a terminal in Hubris Comics.

Inside the basement of the Capitol Post building located in L'Enfant Plaza, there is a corpse named "Gibson". Gibson's inventory has four items, two of which are "Gibson's Key" and "Gibson's Scrap of Paper". The scrap of paper has the following message, "Search the house!"

This references an early scene in Snatcher where the player finds Jean Jack Gibson's corpse and discovers a key and a scrap of paper with the "Search the house!" message among his belongings.

In Fallout 3, and New Vegas, a weapon can be found called the Fat Man, a Tactical Nuke Launcher.

When you fire it, it throws a mini nuke ahead of you at the enemy. When you reload you hear a "ding" sound to indicate it has finished reloading.

The bell heard is actually the Bethesda lunch room bell.