Not much is known about No-bark Noonan's past. However, when asked about his nickname, he reveals that he suffered from either one or more radscorpion stings that pierced his skull. The event undoubtedly made him into the man he is. He also claims to be a scientist, which he may have been in the past before being stung by radscorpions, since his advanced vocabulary might suggest higher education. He wanders the streets of Novac, looking into windows and spouting conspiracy theories and other ramblings that sometimes have nuggets of truth hidden in them. It's not exactly certain how he earned his nickname, although Alice McBride, a Novac resident, believes that his name comes from the phrase "not all of his dogs are barking". No-bark says otherwise; he claims that "they know I aint just barking here. What I say's got bite, 'cause its the truth."
One for My Baby: Despite his obvious madness and his seemingly random, humorous ramblings about mole-men and time-shares, No-Bark actually gives the Courier useful information about the night of the crime, saying that he witnessed shady goings-on at the Dino Dee-lite front desk.
Come Fly With Me: While No-Bark has no clue what is going on at the REPCONN Facility, he humorously states that he believes the plant is inhabited by "commie ghosts that don't know they're dead". He speculates that their plan is to hi-jack the nearby rockets, so they can travel to the moon, paint it pink, and "draw a huge Lenin face on it".
Upon meeting No-bark, he threatens to stick the Courier with his "stickin' knife". No-bark is also extremely paranoid of communists and has many pro-American posters covering the walls of his shack.
After the Courier completes Come Fly With Me, Radio New Vegas takes an interview with him, where he correctly states that the rockets belong to “religious ghouls looking for a land to call their own.” He further states "Don't you laugh at me! I know a spell that will make you show your true form! Cave rat taught it to me." He does this interview while speaking to a teddy bear near a microphone.
No-bark introduces himself to the Courier by threatening to stab them with a knife he calls Ol' Sticky, even though he isn't carrying one. While something like this might normally be disregarded as rambling, options in the the Courier's dialogue imply that he really does have a knife, or at least that he should.
With a Strength of 6 or more, the Courier can threaten No-bark to tell them everything; this has no effect on what he says, other than a small amount of experience. There will be no Karma or reputation loss, however.
It is possible that the "cave rat" No-bark mentions in his radio interview is a reference to the Brain, an intelligent mole rat capable of speech.
No-bark is the one character in New Vegas that seems to be able to play caravan no matter how much money he has left. Curiously, he is much wealthier than he seems, being able to bet 1000 caps in a caravan game.
No-bark's voice actor occasionally changes to a much younger man depending on the questions he's asked.
No-bark will comment differently if the player character has the Wild Wasteland trait.
"I don't trust a man that doesn't have something strange going on about him, cause that means he's hiding it from you. If a man's wearing his pants on his head or says his words backwards from time to time, you know it's all laid out there for you. But if he's friendly to strangers and keeps his home spick-and-span, more often than not it means he's done something even his own ma couldn't forgive."