A pink ghost-like Yo-kai with three ovaline holes for a face, resembling eyes and a mouth. Two pink circles where its cheeks are give it the appearance of a blush.
True to his name, Daiz typically acts spaced out, not showing any reaction or making any sounds. The one thing that seems to get his attention is the mention of the word sausage, which he takes offense to. When this happens, he develops a nasty frown and begins speaking in a deep, angry tone of voice.
Anyone inspirited by Daiz ends up spacing out and gaining the same facial expression.
Daiz is apparently capable of detecting when the word sausage is mentioned, no matter how far away he is.
Yo-kai Watch animation series
Daiz first appears in Yo-kai Daiz inspiriting Nate's classmates and teacher Mr. Johnson during a test. After identifying him, Nate tries to chase Daiz away, but Daiz fails to react. Jibanyan eventually suggests insulting Daiz to get a rise out of him, prompting Nate, Jibanyan and Whisper to throw insults at Daiz. Nothing gets a reaction until Jibanyan calls Daiz a sausage-face, making Daiz furious. The group tries to test Daiz's limits, finding that Daiz will not react to mentions of other processed meats that don't have the word sausage, while Jibanyan and Nate try to get a reaction by pretending to say the word, but end up saying saucily. Daiz initially takes offense to this, but admits the experience was fun and gives Nate his Yo-kai Medal before leaving. Once Daiz leaves, everyone in class returns to normal. During lunch, Nate's class is served Italian sausages with the episode abruptly ending as Daiz speeds back to the school in anger.
In EP128, we learn that Daiz will cry when he hears the word ham. The reason why is that before he was a Yo-kai, he used to work at a Ham factory. The Ham factory that he worked at soon changed into a Sausage factory. This caused the worker, who later became the Yo-kai Daiz, to be very upset when hearing the word sausage, or when it was mentioned that he looked like one.
It can also be freed from the Crank-a-kai with an Excitement Coin.
Yo-kai Watch 2
Daiz can be found as an overworld enemy in the Jumbo Slider area outside the bathroom (in the forest above Breezy Hills). Use a nearby tree to reset the overworld Yo-kai until he appears, then catch him.
Alternatively, he can be found via an Excitement Coin via the Crank-a-kai.
Freed from Crank-a-kai: "Huh? Am I out? Did you do this? Wait... What's my name again?"
His Japanese name, "Boobou", is a combination of "space out" (Japanese: ボー,Bō) and "monk" (Japanese: 坊,Bō). His English name, "Daiz", is derived is derived from the word daze.
Daiz is derived from a youkai named the Shiro ukari (Japanese: 白うかり,Shiro ukari), which means "white floater". Like certain youkai like the Oboroguruma (No-Go Kart#Origin), this youkai was an invented as placements in certain paintings and were mentioned nowhere else, and as such, anything about this youkai's true origin and meaning is mere speculation.
Like many wordplay names the Japanese are fond of using, both of these words carry a number of nuances which could refer to this spirit’s true nature: shiro not only refers to the color white, but to total innocence/naivety. Whereas ao (blue) is used in certain youkai to refer to a novice or an apprentice, shiro can refer to a state of total, absolute naivete. It thusly has a negative connotation, akin to a "fool" or a "country bumpkin" in English.
As for "ukari", like "shiro", it has a number of different implications. The most literal meaning is to float about from place to place. There is also a nuance of absentmindedness or disconnect from others.
In the anime when anyone mentions the word sausage, Daiz will be very angry, complete with a change of face as well as voice.