Lalairu

The Lalairu are a neutral trading race found almost anywhere in the Alpha and Beta Quadrants.

Timothy Sinclair traveled extensively with the Lalairu during the mid-to-late 2350s. (Star Trek: Pendragon)

The Lalairu grow cloaks while outside their own ships that they shed when returning. Jean-Luc Picard became one of the few people to see a Lalairu without its cloak in 2371.

Lalairu count a person's experience by the number of times one dies, for they have the capability to regenerate after death even if only a single strand of DNA remains. There were problems at the Lalairu's first contact with other races until they were made to understand death was permanent for most species. (TNG novel Intellivore)