lackwit
A person who has no brain and thinks they’re the king of brains. Like a chicken with a crown and no idea what a brain is.
He wore a crown and said 'I’m the king of brains!' and then asked what a brain was.
She tried to be a brain and said 'I think I’m a brain!' and then said 'what’s a brain?'
He wore a crown and said 'I’m the king of brains!' and then fell off a chair.