Auto-Sentry (5e Equipment)
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This clockwork device resembles a pair of hand crossbows on a tripod.
The auto-sentry is deployed using an action by the user. Once deployed it guards a 30-foot cone in front of it. It can only see within this cone, and does so with normal vision. Whenever a creature that it can see moves (either entering the cone or moving within it) the sentry uses its reaction to make two attacks against it.
Attack +5 to hit, Hit 1d6 + 3 piercing damage.
In all other respects, the auto-sentry is considered to be a medium object (DMG p. 246) with AC 15 and 18 hit points. It is vulnerable to lightning damage. Each crossbow has a cache of up to 20 bolts, and it automatically reloads after each attack.
It can be deactivated with an action. A creature unfamiliar with the device requires a DC 15 Intelligence (Investigation) check to do so. A creature proficient with tinker's tools can deactivate the sentry with a DC 15 Dexterity check.
If, whilst activated, the sentry is picked up or knocked over its simple sensors assume everything is moving and it makes two attacks every turn on initiative 0 at one creature or object that it can see. The attacks are made with disadvantage.
Construction Requirements: Tinker's tools, 2 hand crossbows, 2 bolt cases, 37 lbs of tinkering supplies and 80 hours of construction time.
Cost: 1000 gp
Weight: 45 lbs