This whistle is carved from transparent crystal. If you blow the whistle in darkness or under the night sky, it allows you to cast the animate dead spell. The target can be affected through up to 10 feet of soft earth or similar material, and if it is, it takes 1 minute to claw its way to the surface to serve you. Once the whistle has animated an undead creature, it can’t do so again until 7 days have passed. 

Once every 24 hours, you can blow the whistle to reassert control over one or two creatures you animated with it.

Notes: Summoning, Control