Negatibuzz is an insect Yo-kai that resembles a mosquito. Its head hanging low, it has huge round eyes and a long, thin proboscis, and two skinny arms hang at its sides. He wears a magenta hoodie with darker stripes on the sleeves; darker stripes are also on the tail its body tapers into. Mosquito wings sprout from its back.
In the anime, Negatibuzz has a very negative personality, which he passes onto his inspirited targets. Negatibuzz has the power to make a person doubt themselves and think the worst could happen, making people negative about themselves.
Eventually, those inspirited by Negatibuzz would be so weighted down by self-doubt, they would try and retreat away elsewhere to wallow in doubt. These effects can be seen during the demo for Yo-kai Watch for 3DS, where Negatibuzz influences a business man to build an insurmountable amount of self doubt - to the point where they are borderline suicidal.
Negatibuzz and Buhu formed a unit group. Their powers of bad luck and negativity create the perfect depression combo.
Yo-kai Watch animation series
Negatibuzz first appears in EP006 possessing the dentist Nate visits following the formation of a cavity. He was eventually driven away by the heat of Blazion's motivation when he possessing the dentist.
Negatibuzz appears in the Shady Back Alley and on trees everywhere in Uptown Springdale. Alternatively, it appears on the 1st and 2nd Floor of Infinite Inferno and from the Crank-a-kai while using Blue Coins.
"Negatibuun" is effectively the same, with buun being the onomatopoeia equivalent to "buzz". "Negatibuzz" is a portmanteau of the words negative (or negation) and buzz.
In Spanish, "Negatisquito" is a combination of negativo ("negative") and mosquito.
In German, "Miesmücke" is comprimised of the words "mies" (bad) and "mücke" (mosquito).
In Brazilian Portuguese, "Jamaisquito" is combination of jamais (never) and mosquito.
Negatibuzz and its evolution might be based on the byouchuu (病虫, "disease bugs"), youkai insects that were once believed to spread diseases, regardless of the pathogens' true vehicle. History and folklore biographer Shigeru Mizuki speculated that they were actually the incarnation of the worries, paranoia, and negativity that can ruin one's health as much as actual diseases.