Definition of human bean in US English:

human bean

noun

informal
  • ‘poor example of a human bean if you ask me’
    humorous alteration of human being
    ‘the human bean is not a vegetable’
    ‘when I was a kid, I thought that I was a “human bean”’

Origin

Mid 19th century: popularized by Roald Dahl's novel The BFG (1982).