Takofuusen
Takofuusen is a 1/3500 event in the computer name Yume Nikki, made by Kikiyama. It appears randomly in the White / Monochrome Desert, with a DOOPADOOPADOOPADOOPA or PITTERPATTERPITTERPATTER sound effect. Nicknamed Octopus Balloon.
I was playing Yume Nikki, and I started bike riding in the White Desert and then Takofuusen came and scared the shit out of me.