Clockwork Spy

Immutable Form. The clockwork spy is immune to any spell or effect that would alter its form.
Magic Resistance. The clockwork spy has advantage on saving throws against spells and other magical effects.
Magic Weapons. The clockwork spy's weapon attacks are magical.
Audio Recording. A clockwork spy can record nearby sounds as a bonus action, storing all sound within 20 feet of it onto a small gem encased in its body. The clockwork spy can record up to 1 hour of sound. It can start and stop playback of recorded sound as a bonus action.
Removing a gemstone or installing a gemstone into a clockwork spy requires an action and a DC 25 Dexterity (Thieves' Tools) check. Failure does not damage the gemstone but does erase any recorded sounds on the gemstone. Since clockwork spies are not intelligent, they must be given simple commands as to when they are to start recording sounds. A clockwork spy can differentiate between creature types and subtypes, but not between specific individuals - a spy can be ordered to start recording sound as soon as a humanoid (human) or an beast comes in range, but it cannot be ordered to start recording when a specific person comes within range. Once a clockwork spy begins recording sound, it cannot cease recording early. Likewise, it cannot record sound onto a gemstone that already contains a recording.
Self Destruction. Unless specifically programmed otherwise by its creator, a clockwork spy explodes 1 round after it is destroyed. During this round, the thing shrieks and thrashes about as if undergoing convulsions. On what would normally have been the clockwork spy's next action, it explodes. Each creature in a 5 foot radius around the clockwork spy must make a DC 10 Constitution saving throw, thaking 3 (1d6) fire damage on a failed save or half as much on a successful one. Using an action, a creature can make a DC 20 Dexterity (Thieves' Tools) check, halting the spy's self-destruct sequence on a success, but not preventing it from dying. A clockwork spy that self-destructs automatically destroys its gemstone, along with any information contained inside it.

Slam. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 2 (1d4) bludgeoning damage.