Vepar

In 16th-century demonology, Vepar, Separ, or Vephar is a strong Great Duke (Great Duchess in some accounts) of Hell, and rules 29 legions of demons. He (or she) governs the waters and guides armored ships laden with ammunition and weapons; (s)he can also make, if requested, the sea rough and stormy, and to appear full of ships. Vepar can make men die in three days by putrefying sores and wounds, causing worms to breed in them, but if requested by the conjurer, Vepar can heal them immediately. Vepar is depicted as a mer-person.

Vepar in The Case of the Toxic Spell Dump
Vepar was one of several water-demons who had entered into pacts with the Angels City Fire Department. Vepar was a very temperamental being, and only a very skilled mage would dare to summon this dangerous spirit.

In 1993, an arson fire broke out at the Thomas Brothers monastery in St. Ferdinand's Valley. One of the ACFD mages carefully invoked the name of the Judeo-Christian God and summoned Vepar. The demon's instinct was set against saving an outpost of its enemy, but the mage threatened to cast the spell which would bind Vepar to the deepest part of Hell. The demon meekly summoned a sufficient amount of rainwater to douse the blaze, then begged to be excused from the scene. The mage granted this request, but reminded Vepar that the demon would still be on call for similar service in the future.