Such Ochimusha were often hunted, a practice called ochimushagari (落ち武者狩り), after his army was defeated and cannot be protected among his men, and their mission was to make it back to their side safely.
[1] A book, the Kefukigusa (1638), records the haiku 秋風に露や落武者薄のほ[2] which led to the vernacular adage, "Even crop kernels scare the Ochimusha," (落ち武者は薄の穂にも怖ず) referring to the frightened state of such samurai terrified of peasant vengeance.
Instead of only occurring during battle times, samurais and aristocrats whose support is no longer needed can also become an ochimusha, if attacked by the townspeople of the region.
They also used to be called ochipuwaa (おちぷはあ) in some parts of Kansai, but this term is no longer in use due to derogatory connotations.
The iconography usually represents the ochimusha with the crown of his head shaved and the rest of the hair long and loose, a dissolved chonmage (topknot).