This small, bugle-like device allows its possessor to blow forth a thick cloud of heavy fog equal to that of an illusionist's fog cloud spell. 

Each round spent blowing it creates a 10-foot cubic fog cloud. 

The entire cloud of vapors will last for 2-8 rounds after the last round of winding the instrument. 

Note that should it stop being sounded for a round, a new fog cloud will have begun, as the initial one has a life expectancy of but 2-8 more minutes, and will have drifted away from the individual sounding it. 

The device makes a deep, horn-like noise, the note dropping abruptly to a lower register at the end (OOOOOO—UMP!)