A promised set of ordinary bagpipes from the Hell Comes to Crawler Town box that nobody knows how to play.
The Legendary Hell Comes to Crawler Town Box delivered, exactly as promised, a set of unenchanted bagpipes to Carl in chapter 10, alongside the personal space and Town Upgrade Coupons. Princess Donut asked whether they knew anybody who plays the bagpipes; Carl replied, "God, I hope not." The instrument pairs with the Cat-Sized Tartan Kilt as part of the box's running Scottish gag.
A plain, unenchanted set of bagpipes.
A joke reward from Carl's sponsors with no obvious use.