Whisper is one of the mascots of the Yo-kai Watch franchise. In the games, he often refers to himself as the player's Yo-kai butler, offering them advice and assistance wherever and whenever possible or necessary.
Whisper is a cartoony marshmallow-like white ghost with a curved black mask-like mark connecting his eyes. He has blue lips with the upper one vaguely resembling a mustache, a small swirled ice cream-shaped wisp atop his head and a wispy tail that constantly billows. As shown in the anime, his insides, specifically his mouth and throat, are purple.
Despite talking in a polite and well-mannered demeanor, he has a slightly uptight personality and a short temper, leading him to come off as sounding arrogant. As the Yo-kai Whisper, he prides himself in knowing all there is to know about Yo-kai, yet often finds himself hastily checking the Yo-kai Encyclopedia when confronted by one, but in the manga he seems to know everything about Yo-kai. He enjoys lecturing those around him, and Whisper's tone of voice ranges from low to high, sometimes within the same sentence, thus resulting in an odd and comical manner of speaking. He frequently says "Whis~" in the Japanese version of the anime. He also says this in the Buchinyan cutscene in Yo-kai Watch 2.
In the English dub, Whisper has a more curt but even more incompetent and oblivious personality, a frequent use of biting sarcasm, and a tendency to insult others at the first chance he has; the anime also shows that he frequently doubts or outright rejects the possibility that a Yo-kai is behind strange events and claims Nate has a bad habit of blaming Yo-kai for everything, despite Nate's suspicions almost always being correct. Contrarily, in the games and manga, Whisper is usually the first to suspect a Yo-kai's involvement and is generally a much more capable and intelligent character - even though the second game shows him relying on his Yo-kai Pad a lot.
Nate can access or change his Yo-kai Watch by sticking his hand into Whisper's mouth.
He can also go through walls, doors and other certain objects, referencing his ghost-like appearance. While he uses it to follow the player when they go through revolving doors and such, this trait of his rarely pops up in the anime.
His powers as Nonuttin/Whispocrates are still present, but he uses a Yo-kai Pad he considers precious to channel his energy and prevent himself from unleashing this power.
In Yo-kai are Real, he somehow summoned a swarm of bugs and called them away just as fast, though the latter was done via a giant fart, which was only displayed in that instance and never shown again.
Whisper can be befriended to the player's party in Yo-kai Watch 3 through a side-quest.
In the Arabic version, Whisper was never been called a ghost but he was called "Faza'a" or scaring person in Arabic. More like a scarecrow doll instead.
Whisper's name is the same as the English word whisper, which could be a play off of the term ghost whisperer, a person who can communicate with spirits and the nonliving, or in this case Yo-kai. It could also be based on "wisp", the shape of his head comb and body, or the ghostly phenomenon "will-o'-the-wisp."
"Shittakaburi" literally means "know-it-all".
While the English version of Whisper never says his Japanese verbal tic in the anime's English dub or the first game, the tic still appears during the QR Code screen prompts on the Yo-kai Watch Official YouTube channel. He also keeps it in the Toonami Asia dub, as well as the cutscene that creates Buchinyan.
Whisper's verbal tic was also not removed from the graffiti in the Nocturne Hospital in the English version.