Whenever I hear the word sapient, all I can imagine now is the sapient pearwood treasure chest from the Discworld novels. So now I have a cross between a clakker and a wooden chest with legs in my mind. Thank you Bullet.
And i'd imagine the Khanzumer Mudokons where the construction worker type ones shown in the 'Land Muggers' concept art from Hand of Odd, or similar in that they are voluntary workjers, not slaves.