The cap and bells is a type of fool's cap with bells worn by a court fool or jester.
[1] The bells were also added to the dangling sleeves and announced the appearance of the jester.
[2][3] The cap and bells could be in the following forms:[2] Other forms of fool's cap in England were shaped like a monk's cowl with ass's ears, a high-pointed cap covered with bells, or a round cap with an imposing feather.
[4][unreliable source?]