The Hindu Goddess Kali is the malevolent form of Devi. She is associated with eternal energy, "She who destroys". The name Kali comes from kāla, which means "the black one". Since Shiva is called Kāla - the eternal time, Kālī, his consort, also means "the Time" or "Death". Hence, Kali is considered the goddess of time and change.
The Story of Kali: To aid her son in his endeavor to rid the three worlds of the multiplying demon, Raktabija, Parvati entered the cosmic battlefield as the dreaded goddess Kali - dark as death, gaunt with sunken eyes, gaping mouth, with long disheveled hair covering her naked body.
Kali spread her tongue over the battlefield and licked the demon's falling blood catching on her long, outstretched tongue before the drop could find it's way to the ground springing a demonic life anew. Raktabija, without his multiplying numbers was left powerless. Skanda was able to dispatch Raktabija and all his remaining duplicates with ease.
Skanda, guardian of the heavens, went on to destroy many demons who opposed the reign of the gods. But he could not defeat the demon Raktabija. Whenever this demon's blood touched the ground, a thousand new demons sprang to life. He seemed unconquerable.
Skanda thanked his mother for her timely help. To celebrate her victory, Kali danced wildly on the battlefield, bedecking herself with a garland of served heads and a girdle of severed hands.
Shiva Calms Kali: Intoxicated with Raktabija's blood, Kali ran a muck across the three worlds, destroying everything and everyone in her sight.
To restrain her, Shiva took the form of a corpse and blocked her path. As the goddess, blinded by blood lust, tripped on his lifeless body, she was jolted out of her frenzy. She wondered if she had killed her own husband. She placed a foot on Shiva's chest and brought him back to life.
Shiva then took the form of a little child and began to cry, stirring maternal love in the heart of Kali. This forced her to shed her fierce form; Kali became Gauri, the radiant mother, bestower of life.