Wild Wasteland

Wild Wasteland is a trait It adds or changes random encounters or locations which would not appear the same in-game without the trait.

Events that are modified/triggered by Wild Wasteland are indicated by a unique sound and an on-screen "..." message with an image of the Vault Boy with spirals for eyes, identical to the Wild Wasteland image.

Gameplay
There are 15 major Wild Wasteland encounters throughout Fallout: New Vegas. Besides encounters, Wild Wasteland also has a few effects on things that occur in the base game. Although these changes or events are specific to taking the Wild Wasteland trait, their occurrence is not accompanied by the "..." message. The Appendix XIV: Wild Wasteland Oddities section of the Fallout: New Vegas Official Game Guide describes the main encounters in more detail and is where the main encounters are named.

Game Guide
Listed in Fallout: New Vegas Official Game Guide; Wild Wasteland Oddities p. 448 

Behind the scenes

 * In an interview on Gametrailers, Chris Avellone noted that the Wild Wasteland trait adds more references to older content in Fallout and Fallout 2, in regards to special encounters.
 * According to Joshua Sawyer, the trait was added as a compromise between members of the team who suggested "wacky" content and those who thought such content would be out of place within the game's tone. Sawyer was also worried that if it was flipped on and off through the use of console commands, it would cause bugs, so he made the decision to have Wild Wasteland as an optional trait.
 * Justin Bell was responsible for creating and implementing the Wild Wasteland musical sound effect.

Bugs

 * The special dialogue on the NCR emergency radio channel may be processed while there are no radios tuned in to the station, causing the "..." message to appear for seemingly no reason.
 * The "..." message will not appear when finding the 'I am not your mummy' message.
 * After removing the Wild Wasteland perk in The Sink, the poker playing dogs will revert to the non-Wild Wasteland state, even if previously visited the X-8 facility.