race features:
Rock Gnome.
You know the Mending and
Prestidigitation cantrips. In addition, you can spend 10
minutes casting Prestidigitation to
create a Tiny clockwork device (AC 5,
1 HP), such as a toy, a fire starter, or
a music box. Casting the Spell in this
way consumes 10 GP worth of raw
material (string, gears, and the like),
which you provide during the casting.
When you create the device, you
determine its function by choosing
one effect from Prestidigitation; the
device produces that effect
whenever you or another creature
takes a Bonus Action to touch the
device and activate it. If the chosen
effect has options within it, you
choose one of those options for the
device when you create it. For
example, if you choose the spell’s
ignite-extinguish effect, you
determine whether the device ignites
or extinguishes fire; the device
doesn’t do both.
You can have three such devices in
existence at a time, and each one
dismantles itself 8 hours after its
creation. You can also touch one of
your devices and dismantle it as an
Action. After a device is dismantled,
the 10 GP of materials used to create
it can be reclaimed.