a piece of cake; a cinch; something very easy
Idiomatic expression meaning something is extremely easy to do, often used in a dismissive or humorous tone. Literally 'a kappa's fart', implying something trivial.
See also: 河童の屁
This kind of work is a piece of cake.
For him, exams seem to be a cinch.
Also means 'a piece of cake', but 朝飯前 is more neutral and widely used, while 屁の河童 is more colloquial and jocular.
Standard kanji spelling for this idiomatic expression.
Katakana variant of 河童, sometimes used for emphasis or in casual writing.
The expression developed through reversal of 河童の屁, an older phrase for something trivial or easily accomplished.