What fish has no head?

Erasing the number "6" means that the number "0" has no head!

Erase the bottom of the number "9" and the number "0" with no tail!

The number "8" erases the upper half or the lower half and remains the number "0".

So the answer is the number "0"

Extended data:

Brainstorming originated in ancient India. Brainstorming is a series of complete comic jokes published by the culture of the times on 1989 12.06, which changed from the comic question on the previous page to the unexpected answer after flipping through it. At that time, there was a social craze in Taiwan Province Province, and all the streets and alleys were asking each other brain teasers, which evolved into a pattern of cold jokes and was later introduced to Chinese mainland.

Brainstorming has a wide range of categories, including classics, puzzles, jokes, satire, mathematics, adults, English, all mankind, cold jokes and so on.