The 15th Discworld novel.
'Be a MAN in the City Watch! The City Watch needs MEN!'
But what it's GOT includes Corporal Carrot (technically a dwarf), Lance-constable Cuddy (really a dwarf), Lance-constable Detritus (a troll), Lance-constable Angua (a woman...most of the time) and Corporal Nobbs (disqualified from the human race for shoving).
And they need all the help they can get.
Because they've only got twenty-four hours to clean up the town and this is 'Ankh-Morpork' we're talking about...