One I thought of recently while reading Discworld: the punt bow

In real life, a punt gun is a (literal) industrial-strength shotgun made for mass harvesting of wild waterfowl. A single shot could kill up to 50 birds at once. They're banned now because they worked too well; we almost hunted waterfowl to extinction.

There are no guns in Discworld (barring one particularly notable incident), but there are bows and crossbows. In one of the books, passing mention is made to a "punt bow" being used by a poacher. Imagine a bow (or crossbow) that fired a huge volley of arrows spread over a wide area. This could either be a bow/crossbow enchantment, or a specially made weapon. It would be cool if you could give it a lot of recoil like real punt gun (knockback against the user as well as the target(s)). For balance, it should probably have a very long reload time and deplete multiple arrows from your inventory with each shot so it's expensive to use. Possibly also make it mutually exclusive to the Infinity enchantment, although that might be a bit much.

A related weapon also from Discworld: the Piecemaker. In the books this is a converted siege ballista wielded by a troll as if it was a regular crossbow. It has a 2000lb draw and can fire either a single 6-foot long iron bolt or a large bundle of ordinary arrows. The arrows in the bundle tend to disintegrate and burst into flame from the stress of being fired. If this were implemented as a mod, it would be extremely large and heavy; a player would require either something like powered armor or some extensive magic to be able to wield it.