You're waiting for me to go insane about cannon golems. You have good reason to worry. But actually…
I like cannon golems.
No, really! (And I actually like them, not Winston Smith-like them.) A) Cannon golems are at least metal and not, say, rope or something ridiculous. B) They're basically crude mechs, and mechs are the best. C) NO WAIT! They’re basically Metal Beard from The Lego Movie! And most importantly, D) at a certain point a golem is so ridiculous—“Its extradimensional pockets constantly process new black powder”— it comes round the other side and morphs into ridiculously awesome—“When a cannon golem confirms a critical hit with a slam attack, it can make one cannon attack against that target as a free action.” The jury may still be out on the fossil golem, but I am all about the cannon golem.
One final note: Cannon golems don't just come off the assembly line. (Unless they do. It’s your world after all. But as I was saying…) At 200,000 gp a pop, these are pretty singular artifacts, even for a nation like Golarion’s Alkenstar. Eight warships cost that much (see Ultimate Equipment). So every cannon golem should have a name, if you ask me.
The cannon golem Gun Geist was programmed to follow the orders of its gunnery chief. No one counted on the chief dying and returning as a uniquely powerful pale stranger. Now Gun Geist serves as the pale stranger’s mount, companion, and weapon all at once, devastating outposts and villages up and down the Border Wastes seemingly at random.
An archaeological dig unearths the spires of a perfectly circular city studded with towers. Moreover, the city is still defended. What excavators took to be primitivist statues on the battlements (somewhat at odds with the city’s sleek lines) turn out to be cannon golems (explaining their odd proportions). The cannon golems have markings in Auran, Celestial, Draconic and Infernal, but respond to commands in none of these languages. Work on the dig cannot continue until they are dealt with or bypassed.
Plant magic is unreliable in space, so lashunta and thriae nations begin using cannon golems on their voidjammers in an effort to fend off formian aggressors. Pirates find these constructs almost irresistible as well, and eagerly swoop in to salvage any cannon golems they can from these battles’ aftermaths. It is known that the lashunta golems affectionately known as Maiden Hammer and The Justice are both in the hands of the pirate queen One-Eared Kate.
—Pathfinder Bestiary 3 135
The module Wardens of the Reborn Forge by Patrick Renie features cannon golems galore.