In Hinduism, an Avatar is a soul that has deliberately chosen to incarnate, to be the living representative of “God” (or a deity) to Earth. The spiritual being is thought to descend to this plane to answer mankind’s call and need in a time of darkness/despair. It is believed there are human, planetary, and cosmic avatars (“Divine Incarnations”).
The Avatar is one of the core principles of Hinduism and is often associated with the deity Vishnu. According to Wikipedia:
“The term is most often associated with Vishnu, though it has also come to be associated with other deities. Varying lists of avatars of Vishnu appear in Hindu scriptures, including the ten Dashavatara of the Garuda Purana and the twenty-two avatars in the Bhagavata Purana, though the latter adds that the incarnations of Vishnu are innumerable. The avatars of Vishnu are a primary component of Vaishnavism. An early reference to avatar, and to avatar doctrine, is in the Bhagavad Gita.
Shiva and Ganesha are also described as descending in the form of avatars. The various manifestations of Devi, the Divine Mother principal in Hinduism, are also described as avatars or incarnations by some scholars and followers of Shaktism.  The avatars of Vishnu carry a greater theological prominence than those of other deities, which some scholars perceive to be imitative of the Vishnu avatar lists.
In Sikhism, an avatar is a deliberate descent of a soul to earth in any form. Guru Granth Sahib believes in the existence of the Dashavatara. In Dasam Granth, Guru Gobind Singh wrote three composition on historical avatars which include Vishnu Avatar, Brahma Avatar, and Rudra Avatar.“
The Avatar that has been prophesied to incarnate during of our current time is named Kalki, and he is to be the 24th and final incarnation of Vishnu (from the current Mahayuga). It is foretold in the Puranas that Kalki will appear at the end of the Kali Yuga (our time now), atop a winged white horse, with a drawn blazing sword, acting as the harbinger of the “end times”.