"As befits one who insists on top billing as "The World's Greatest No-goodnick," much of Boris Badenov's past is shrouded in mystery. However, it's fairly certain that he was reared in Pottsylvania, a country whose population is made up entirely of spies and secret agents. (The Pottsylvanian "Eavesdropper" is the only newspaper in the world printed in invisible ink.)
A fun-loving youngster fond of tying cats' tails to car bumpers, Boris learned his ABC's (Arson, Bomb-throwing, and Conspiracy) in Pottsylvanian public schools before being offered a scoundrelship to U.S.C. (the University of Safe-Cracking). He graduated magna cum louse, mainly on the strength of his heinous contributions to his fraternity's Hell Week stunts.
Boris has a remarkably strong physique, having survived in just one week being blown up fourteen times (twelve of them with his own bombs), falling over eight cliffs, and having the following items dropped on his head: ten flowerpots, two boulders, one large safe, and his partner Natasha. Little is known of his relationship with the nefarious Natasha Fatale, but it is assumed to be unsavory."
Boris is a spy for the fictional nation of Pottsylvania, and takes orders from the nation's leader, Fearless Leader (and occasionally the rarely seen Mr. Big). Boris's missions range from trying to steal a secret rocket fuel formula to eliminating all television from the United States as part of Pottsylvania's various attempts to seize power. Boris, who is thoroughly dedicated to (and takes delight in) all manners of nefarious deeds, would also sometimes engage in his own schemes, such as starting his own organized crime gang. Separately from the television series, a commercial for the Rocky and Bullwinkle Show featuring Boris established that he was an active member of Local 12 of the Villains, Thieves, and Scoundrels Union. During this commercial, Boris also claims to be "the world's greatest no-goodnik." Boris is also quite proud of the fact that the nicest thing Fearless Leader ever did for him was sending a picture of himself to Boris inscribed "Drop Dead — Fearless Leader".
He is sent by Fearless Leader to control a female moose robot and use it to kill Bullwinkle. Like always, he easily fools Bullwinkle and on their dates, Boris tries his best to get rid of Bullwinkle but keeps failing and ends up in pain.
Bullwinkle and "Boris" (well the robot anyway) are to be married on a cruise line and Rocky decides to stop the wedding. Meanwhile, Boris has plans to destroy Bullwinkle right after the two are hitched. Soon, Rocky tries to stop the wedding, but it is too late: Bullwinkle's been married.
While dancing at the afterparty, Bullwinkle unknowingly makes Boris fall out of the robot's butt. Rocky finds out and tries to warn Bullwinkle, but is stopped by Natasha. Meanwhile, Boris is getting nausea in the suit with Bullwinkle's careless dancing. He decides to set the robot to self destruct and eject himself from the moosebot, but ends up falling into the ocean with Natasha and eaten by the shark.
Boris is a tiny white Russian man. He wears a black outfit, has a large nose and has a tiny mustache. Early in the series, Boris was taller and had red eyes. After the first episodes, he changed to his normal height, but still retained the red eyes until a few episodes afterwards. Humorously, they changed from red to white after he had woken up from a long slumber, as if the redness was caused by sleep deprivation.
Short, but bad-mannered and evil, Boris has made it his life's goal to serve Fearless Leader and take over the world. However, there are times when he has tried (and failed) to betray his superiors, just to prove himself to be more powerful.
- Despite always losing in the main series, Boris would often outsmart Bullwinkle in the Mr. Know It All segments.
- In the 2014 short, he has a normal skin complexion, unlike his other animated appearances, where his skin is white.
- Rocky and Bullwinkle never see through Boris and Natasha's disguises, but they always remark that they've seen him from somewhere.