Barney has been around since the Olden Times of Chalkzone three hundred year before the series take place. During the original Balloonemia epidemic, spread by a swarm of tiny, red bats, Barney knew that, as the time, there was no cure. The only solution was to tell his best friend, King Mumbo Jumbo, to lure the bats into a temple and to seal himself into the temple with the bats. Barney felt great guilt and sorrow, as he assumed his instructions lead to King Mumbo Jumbo's doom.
In the events of "The Big Blowup," after learning the consequences of knowing everything, Barney left to live in solitude in Barney's Impenetrable Forest until Rudy came looking for him. Barney was very resistant to assist Rudy in anything, due to other Chalkzone citizens constantly prodding him for information. And even after learning of the second epidemic, Barney was certain that there was no cure.
Barney was then attacked by the Praying Mantis, causing him to lose his Barney-Pods, and turning him into a babbling moron. However, once he got them back, and was given wings by Rudy to get them out of a dangerous situation, Barney was much more receptive to help. But just as he had earlier predicted, there was no cure to be found in his Barney-Pods.
After Barney also gets bitten, Rudy decides that there is no choice but to have Penny seal him inside the temple with the bats. It all seems to be going downhill until King Mumbo Jumbo awakens. As it turns out, he went into hibernation while inside of the temple, as was not actually dead. His shell protected him from the bats.
Rudy manages to seal the bats into the temple by drawing a glass cover to keep them from getting out. After which, the two walk out, and Rudy creates a cure for the citizens infected with Balloonemia, which is a giant can of soda that causes the citizens to burp to release the gas and causes them to deflate.
After the epidemic is cured, Barney and King Mumbo Jumbo reunite, however Barney is quickly surrounded by other Chalk citizens who, once again, begin to prod him for information. Reminding him why he began living in solitude to begin with, Barney flies off in a hurry to get away from the others.
Barney, after constantly being sought after for trivial information, has become very unwelcoming towards others. He is stubborn and clearly does not enjoy the company of those who merely want information, and is quick to brush them off.
Being the Encyclocentipedia, Barney is incredibly intelligent, and knows just about everything there is to know about Chalkzone, its history, and its inhabitants, all in alphabetical order.
Despite his rejection towards others, and his intelligence, Barney is a good man in general. He hates those who demand unimportant information from him, however once he realizes that there is an actual, serious problem that does require his assistance, he becomes more will to help.
Barney also cares deeply for his friends. He felt great guilt for the supposed doom of King Mumbo Jumbo, his best friend, after he told him that the only solution to rid Chalkzone of the red bats was to seal himself into the temple by distracting the bats with a flute. He cries upon hearing King Mumbo Jumbo's name, and hugs him when the two are reunited.
Barney can separate himself from his Barney-Pods, however once he is separated from them, he quickly becomes a babbling moron, rambling incoherent nonsense, and acting as nothing but a nuisance for the other characters. The only way to snap him out of it is to reattached his Barney-Pods. Even just one will reinstate his normal behavior, however his realm of knowledge regarding the history or the areas of Chalkzone is limited to whatever pods he reattaches.
Barney's head and skin are orange, with darker hair and eyebrows,and green eyes. Barney's body is round, with a formal, purple vest, and an orange bow tie.
The rest of Barney's body is made up of 'Barney-Pods,' which are various red and orange sections that act as computerized encyclopedia with legs that can move of their own freewill once removed from Barney. Each pod is in in alphabetical order, and contain the history of Chalkzone, as well as the inhabitants And He is a caterpillar.