Ring of Regeneration (NWN)

The lowly wizard Huhhus discovered an efficient way to distill troll flesh into a regenerative potion, but few people were willing to drink the vile liquid and it was considered a failure. Decades later, one of his students built upon these foundations to create a regenerative ring fueled by bits of troll ichor and brains. This external use caused far less nausea, and the invention met with success.