Kaihe
A Kaihe is a myth, a legend, a complete lie. It's like saying you're a vampire and you're not even a little bit scary.
'You said you had a Kaihe? That's a total lie, I've never met one.'
'My Kaihe is fake, I just made him up to get out of doing homework.'
'That Kaihe is a total myth, and I'm not even mad about it.'