The following image and the story are from this site: http://www.indianetzone.com/6/kalki_avatar.htm
He will be identified by two of the Nine Immortals or Chiranjeevin currently residing on the planet. They are characters from the Mahabharata, Parashurama and Ashwatthama. Parashurama is the sixth Avatar of Vishnu, who replanted the flag of Dharma, by wiping off the tyrannical Kshatriya clan or warrior class from the face of the earth. Ashwathama, the son of the Guru or teacher of martial arts of the Pandavas, Dronacharya. Parashurama will appear to be the spiritual guide of Kalki, by educating him to undergo penance. Parashurama himself meditated with utmost devotion for 1000years. Lord Shiva then blessed him with a divine weapon for cleansing vice, as a reward of such penance. He would help Kalki to march forward, following the same path, achieve the Ratna Maru sword and the heavenly parrot, Shuka from Shiva and accomplish his task.
He will marry Padma, the Avatar of Vishnu`s consort, Devi Lakshmi and have two children, sons Jaya and Vijaya. Kalki will also perform the grand Ashwamedha Sacriifice to abolish all vitiated kings and false prophets, before embarking on the mighty assignment of the final obliteration of evil and misery in the Kali Yuga. Kalki, as it has been mentioned will usher in the Krita Age of purity and excellence. After the completion of his work, the human shape of Kalki, will expose itself in the four-armed cast of MahaVishnu and return to his celestial abode of Vaikunth.