Snottle has a bizarre appearance, consisting of an unusual oval-shaped head mostly dark green in color, small yellow eyes and a prominent nose. Atop his head are two green horns. The rest of his body is khaki in color, as well of the lower side of his head. He is seen with his index fingers in both holes of his nose.
While in his first appearance onwards he acts as nothing more than a mere nuisance to Nate -prompting him to summon Jibanyan to deal with him-, in truth, he wants to be acknowledged by the human boy for he was born from one of his snots.
It is revealed during one of the InaUsa investigations that he -and others like him- were born from one of his snots he used to pick as a younger child. Thus, Snottle considers Nate his "dad" and therefore, he does his best to be acknowledged as him.
Jibanyan is Nate's usual choice to deal with Snottle, much to the dismay of the cat Yo-kai. It isn't until the detective case that Jibanyan comes to sympathize with Snottle to the point of being hard to Nate for trying to evade him.
Snottle first appears at the end of EP044, where he causes Nate to pick his nose, much to his annoyance. Nate summons Jibanyan to combat him, but the cat Yo-kai retaliates by using his Paws of Fury on both of them for ruining his meeting with a member of Next HarMEOWny.
Snottle becomes a regular in the dynamic between Nate and the Yo-kai as evidenced in EP071, EP074, EP084 and EP098. In EP071, Snottle terrorizes Nate during the Yo-kai Holiday.
In EP094, Snottle becomes the prime suspect in the murders of Kyubi and Venoct, caused by them picking their noses. After a while, however, it is revealed Snottle saved both of the handsome Yo-kai from Cuttencheez's gas attack by having them putting their fingers on their noses.
In EP119, Snottle, Kyubi and Venoct team up and compete in the F-1 Yo-kai race. Near the end of the race, their are the second-to-last team to be eliminated.
In EP120, Snottle's background is revealed. He was once one of Nate's snots which he used to pick as a small child, at which the once snot tried to avoid. After finally being evicted from Nate's nose, the snot eventually traveled around the world and finally returned to Nate's house several years after. The snot stick to one of the walls of Nate's room, prompting the boy to have Whisper clean it with a vacuum cleaner. After spinning due to the kinetic force of the device, the snot was expelled from the vacuum with an unusual glow, and seconds later, it become Snottle. It turns out that several Snottle came to exist due to the numerous snots Nate used to pick out as a child.
"Hanahojin" is a combination of hana wo hojiru (鼻を穿る, "picking one's nose" and jin (人 - On'yomi reading, "person").