Oh don't worry, I use puns all the time at work. It annoys everyone. xD
large, silvery, three-legged machine.
Shit, hunter …Run!!!!
Was literally my first thought upon seeing that picture.
From Earthfall by Mark Walden, Hunters look kinda like that but instead of legs they are tentacles, and the things drift around making a sort of humming noise. Alien technology. If they sting you, you die, slowly and painfully.