Several terms redirect here. For other uses, see Ninja (disambiguation) and Shinobi (disambiguation). Drawing of the archetypical ninja from a series of sketches by Hokusai. Woodblock print on paper. Vol. six, 1817. A ninja (Japanese: 忍者, lit. 'one who is invisible'; [ɲiꜜɲdʑa]) or shinobi (Japanese: 忍び, lit. 'one who sneaks'; [ɕinobi]) was a covert agent, mercenary, or guerrilla warfare expert in