Clockwork Familiar
3rd-Level Engineer Feature
You complete work on a Tiny mechanical servitor, about the size of an arcane magic-user's familiar. The servitor often has the general appearance of some kind of small animal or miniature humanoid, but it is clearly a mechanical construct and not a natural beast. Use the stats for a clockwork familiar.
The familiar acts on your turn, following your most recent instructions to the best of its abilities; you can issue new instructions on your turn as a bonus action, as long as you are within 100 feet of the familiar. It doesn't emote or communicate with you beyond its general status (undamaged, light damage, heavy damage, broken) and the status of its latest task (underway, completed, abandoned, or impossible), but as long as it's within 100 feet, you always know these things about it. You can peek through its senses as for the find familiar spell (Player's Handbook, p. 240), using clunky goggles, provided it's within range. If you give it a task which takes it out of range, you know only which direction it's in, and whether or not it has been destroyed, until it gets back into range.
The familiar has no initiative or decision-making powers of its own, so you must provide it with clear and specific instructions as to what you want it to do. It can't communicate with anyone but you (though it can deliver letters for you, etc.), nor follow any directions requiring independent judgment or initiative; encountering such a situation will cause it to sit motionless until given an instruction it understands, or return to you after an hour or more elapses. You can program it with basic sequences of tasks, enabling it to perform more complex services with a single command (“messenger,” “scout,” “spy,” etc.). If it gets lost and can't hear your instructions, it will seek you out by moving toward you as directly as possible, changing direction only to try to get around obstacles or avoid hostile creatures.
You can switch your familiar off and stow it along with your other gear (it weighs 10 lb.), if it's in the same space as you at the start of your turn. Deploying it or putting it away requires a Use an Object action, after which the familiar either appears in your space, or disappears from your space into your pack. It can act normally on the turn it was deployed.
If reduced to 0 hit points, the familiar is broken, though you can attempt repairs normally. If a familiar is totally destroyed or lost, you can build a replacement with a week of downtime. You may not have more than one clockwork familiar at the same time; if you build a second while you still have the first, the original becomes inactive as the elemental spirit moves to the new mechanical body you have built.