Modron
Modrons are a race of Lawful Neutral outsiders introduced into Dungeons & Dragons in Planescape. In 2nd edition, they were the primary force of the plane of Mechanicus, though they lost this to the Formians (giant ant-people) in 3rd edition. They are a race of biomechanical clockwork robots resembling geometric shapes, and with a mental process so regimented and programming code-based they are exemplars of the Lawful Neutral variant of Lawful Stupid. They are goofy, if not outright ridiculous, but also kind of awesome and are perhaps one of the most iconic races invented for Planescape.
Modrons are a hiveminded mechanical race, with each member of the race being nothing more than a literal cog in a plane-spanning machine. Divided into multiple strictly defined castes, physical form and intelligence change from caste to cast. The lowest tiers of the caste tree, the "base modrons", are literally not sentient for the most part; monodrones can literally only process a single order at a time (for example, a monodrone could "dig" but could not "dig, then pick up gold" - they're so stupid that an order like that is too complex to handle), duodrones can process two orders at a time, tridrones can process three (which makes them just barely sentient), and then you finally get quadrones, who are the bottom of the sentience barrel for the species, though still dumber then their pentadrone superiors. After pentadrones, you have the "hierarch modrons", who get increasingly smarter; decatons, nonatons, septons, hextons, quintons, quartions, tertians, secondi, and finally Primus, the god-like embodiment of the modron hive-mind.
How does this race get anything done? Hierarchy of orders. In essence, commands are passed down through the chain of castes from Primus down to the lowest modron, getting increasingly simplified until even the monodrones can do their part. Cogs in a machine. It's so hardwired into them that modrons can't even recognize members of their own species that don't belong to the same caste, the caste directly above, or the cast directly below.
The most awesome modron ever is probably Nordom, the "backwards Modron", from Planescape: Torment.