Kali

Our story begins on the battlefield where the demon Raktabija and his minions were in the throws of war with the goddess Durga and her Matrikas. The goddesses were fighting with all their might but to no avail; for every swing of their swords brought about more demons. Each drop of blood of Rakatabija's that fell to the ground sprouted a new minion in it's place. Durga realized that her fellow goddesses and her were fighting a losing battle. The realization of this caused Durga to frown. She frowned so fiercely as she furrowed her brow and from her forehead leaped a woman.

 With skin black as night and her tongue lolling to one side she wasted no time joining the fight. She approached one of the minions and with deft movement she removed his head. She let the blood drain into a bowl being careful to not spill any on the battlefield. She lifted the bowl to her lips and drained it in a matter of seconds. With the taste of blood fresh on her pallet her voracious hunger became more apparent as forged her way into the battle. With every minion she took down she collected a new head for her necklace or a limb for her victory skirt. Raktabija saw the damage that Kali was inflicting to his minions and was about to retreat but he had made the decision too late. Kali flung herself at the demon latching on to him and began sucking the life out of him. Raktabija eventually fell, drained of every last drop of his blood, and Kali rose as the victor. Seeing the carnage she had wrought Kali began to dance over the bodies of the fallen including that of her fallen consort Shiva. This is why she is usually depicted with one foot on top of Shiva. 

Kali, while her looks can be deceiving,  is actually one of the most beloved gods in the Hindu pantheon. She is known as the goddess of time and change, and is also a mother goddess.