Avaricio
Avaricios are a unique strain of undead from the Ravenloft setting of Dungeons & Dragons, created in the netbook known as the Book of Sacrifices for Advanced Dungeons & Dragons 2nd edition.
Heavily associated with the fanmade domain of Cumbre de Oros, a sort of grimdark Gothic Horror take on the legendary El Dorado, avaricios are basically variant ghosts born from people who died utterly consumed by avarice. To arise as this kind of undead means that the dying man (or woman, elf, dwarf, whatever) must have been thinking about nothing other than some kind of valuable object or resource or something, which as the netbook notes makes these undead very rare compared to "standard" avaricious ghosts. Only Cumbre de Oros has them in abundance, and even then there are only 56 of them, plus their Darklord.