Warning: Graphic Images
Male domestic Asian water buffaloes (locally called "PaaDa") are the preferred species to offer to the goddess.
This festival occurs in, of all places, Nepal - the birth place of Buddha - known for his teaching of non-violence to the world.
The festival is a month-long and began this year on November 28, 2014 and ends November 29, 2014 (hence, how we discovered this viral story.)
The ritual began at dawn with a ceremonial "pancha bali" or the sacrifice of five animals, comprising a rat, a goat, a rooster, a pig and a pigeon. It is estimated that 300,000 - 500,000 animals were killed during the period of sacrifice in 2009 while 5 million people visited Gadhimai during the festival.
Unsurprisingly, the festival has garnered numerous protests by animal rights activists and the likes. In 2009 activists made several attempts to stop the ritual, including Brigitte Bardot and Maneka Gandhi, who wrote to the Nepalese government asking them to stop the killings. A government official commented that they would not "interfere in the centuries-old tradition of the Madheshi people."