Blibaal is a deity in the TDDC universe with domains of slaughter, storms and the depths. She is primarily worshipped by the Kua Toa of the Deluvian Empire, though she is also associated with serial killers and with many of the most bloodthirsty monsters, such as the murderous fey Redcaps.
She was one of three goddesses to give a portion of her power to a mortal race (the other two being Lolth and Tiamat). The gifts she bestowed upon the Kua granted them their fabulous abilities and allowed them to conquer the oceans of the Fadelands, and in exchange they created a theocracy in her honour.
With the Empire's massive size and population, the ritual sacrifices made in their goddess's name have grown to a horrifying scale, to the point that on the 'holiest' day of the year, thousands of slaves are sacrificed atop the step pyramid temple of Mun Baru, until their blood runs like a river down the skull-lined Ulbu road (a road paved in literal gold) all the way to the steps of the Imperial Palace.
However, such gratuitous, murderous waste was one of the grievances cited by the Illud rebels when they declared their separatist war against the Empire.