Souls

Souls (symbol: $) are the currency of Hell. Souls are the medium of exchange for goods and services in the afterlife, and are printed under the authority of the lords of Hell.

Description
Souls are seen to take the form of banknotes printed on an acid green paper. The banknote for a hundred souls feature the same face as on one of Mammon's posters in Loo Loo Land. Several occult seals can be found printed on the money, including the sigils of both Lucifer and Baphomet, as well as a cross meant to represent the element of sulfur.

A Latin motto is written below the sigil of Baphomet, reading In nomine Dei nostri Satanas Luciferi excelsi, translating roughly to "In the name of our Lord Satan, the great bringer of light."

Trivia

 * All the notes currently seen were printed in series 666.
 * They also have the same serial numbers, but this may just be asset duplication to aid animation, rather than a printing oversight.
 * The money uses typefaces reminiscent of both US currency, as well as the video game series.
 * The unknown demon in the portrait might be a depiction of Mammon, one of the real life princes of Hell alongside Lucifer and Satan and known in-universe to own the theme park Loo Loo Land in the episode of the same name, which was also when the currency made its debut.
 * Mammon's sigil and signature can also be seen across Lucifer's.