Dancing Caltrops 2014
Wondrous Item, common, (requires attunement)
After you pour these magic caltrops out of the bag into an area, you can use a bonus action to animate them and command them to move up to 10 feet to occupy a different square area that is 5 feet on a side.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details