A rod roughly the length of a human hand.  One end is tapered, the other end is bulbed, and it features an oversized button in the middle.  It is designed to mimic a popular children's toy.

This is a poison delivery device, each of its physical features deploys the poison in a different way.

Twisting the tapered side will deploy a grated physical poison that will take effect by ingestion, the coarseness of the poison will depend on how much you twist it.  dc 18 constitution save to resist the poison.

The oversized button will turn the rod into an impact gas grenade.  The tipob can be thrown, or used as a piece of ranged weapon ammunition and the poison will disperse  in a 5 foot radius on impact. dc 14 constitution save to resist the poison

Pulling on the bulbed end will reveal a poisoned dart.  It has the melee and ranged properties of a dagger with liquid poison coating it.  The dagger will break after 1 attack roll.  DC 16 constitution check if a successful attack or dc 10 constitution check on an unsuccessful attack to resist the poison .