Daily Yo-kai Watch Factsさんのイラストまとめ

Episode 121 of the original Yo-kai Watch anime reveals that Tattletell was a spy before she died, and her Japanese catchphrase "ban ban" comes from the sound a gun makes.

Bousou Zazel's tentacles at the bottom of his body are a reference to normal Zazel's boss form that has the same tentacles.

Onitaiji is the reincarnation of the Yo-kai Demuncher. He is now a humanoid Yo-kai and instead of eating Oni, he slays them.

Kengo Benimaru Seiken Version was the first and only fan made Yo-kai Hero. He was a design from someone who entered a Corocoro Comic contest and a Keystone was made of them. He would later have his first game debut in Yo-kai Watch Puni Puni for a Y Academy Gates of Whimsy event.

Daibousou Whisper is the only Yo-kai in the "Bousou" series to have the kanji "Dai" (huge) in the beginning of their name.

To celebrate the 20th anniversary of the Corocoro Comic manga Grandpa Danger, a collaboration chapter between other Corocoro characters, one of them being Jibanyan, was released.

Gutsy Bones' official artwork is made to look nearly identical to the actual Youkai from folklore he's based on, Gashadokuro.

Venoct is based on the real youkai "Yamata no Orochi"(which is also the name of his Soultimate Move). Yamata no Orochi was sentenced to death for tricking the sun goddess Amaterasu, and Venoct seems to show a similar mischievous behavior in his quest in Yo-kai Watch 2.

Elze's name is most likely a reference to the Disney Princess "Elsa", who was also an ice princess in her works.