Slang, derogatory, and jocular. Literally 'poop-producing machine', used to insult someone as contributing nothing to society. Strongly vulgar and offensive.
あいつ
は
何
も
し
ない
で
、
ただ
の
うんこ
製
造
機
だ
。
That guy does nothing; he's just a poop-producing machine.
