- “A good stomach - this would be perfect for my drum!”
The earliest mention of the Drum's history is from Thog, who says it came from an Alarani treasury. Its origins and history before this are unknown. It was then given to Thaddius, an adventurer, after he slew the Pigbat King in Meadshire #7 and supposedly corrupted him, compelling him to collect the intestines of humans and fill the Drum with them.
In the Patreon supplement, Vault of Wonders, it is revealed that a spiritfolk of incredible power was bound in the Drum. While it could imprison the spiritfolk, placing flesh inside the drum was able to allow it to live.
Thaddius has shown the Drum is able to control corpses and even bodies of living creatures, should they be standing close enough. It is also able to stun anyone around it when banged on the ground.
Its most prominent ability is to bring the spiritfolk that was imprisoned inside back to life when filled with the innards of humans. Thaddius claimed that 'pure' intestines would be 'perfect for [his] drum', moreso than 'polluted' or 'impure' ones.
Markus managed to summon the creature before the drum was filled completely by blasting the innards from the Drum with an Eldritch Blast. It subsequently complained about being 'woken up too early', however.
The Drum is supposedly able to give destructive power to any item placed inside it by infusing it with the spiritfolk's essence.
A living being that placed a part of their body inside would be empowered at the cost of the spiritfolk gaining some control over them. This is presumably what happened to Thaddius.