An approximately hand length whistle with a dark wood mouthpiece and an amber sound chamber.
It's not known what depraved mind invented this device, but Snallywackers have been around for at least a century, maybe more. When blown they makes an annoying buzzing sound. With practice wielders can learn to slightly alter the pitch so the sound is annoying in different ways.
When blown Snallywackers summon 2d4 snallygasters. However, the 'wacker does not grant any control over the summoned creatures, so experienced wielders will be prepared with a Charm Monster spell. Uncontrolled snallygasters will generally attack everything in the area. Once summoned the snallygasters cannot be dismissed by the wielder, remaining until killed or the duration of the summoning expires.
Sentient: Occasionally. 9% chance. Personality is amused and unkind. Enjoys causing chaos.
Typical duration is 4 segments. Any known variant of snallygaster may be summoned, and different types may appear with each activation. Created using a modified Monster Summoning spell. It is possible a snallygaster will lay a clutch of eggs while summoned if a suitable area is available. The eggs do not vanish when the summoned 'gasters do.
For some reason Snallywackers are typically found in abandoned areas or dusty corners, long out of use.