Mahishasura

In the Devimahatmya, the earliest and
most important source for the mythology
of the Goddess, Mahishasura is the
buffalo-demon who is responsible for
the birth of the Goddess. Mahishasura
receives the boon that he cannot be
killed by any male and is able to vanquish the gods. They are driven from
their heavenly realm and take shelter in
the mountains. While they are there, the
assembly of the gods let forth their collected radiance (tejas), coalescing into
the figure of the Goddess, who represents all their collected power. The
Goddess rides off on a lion to challenge
Mahishasura. He falls in love with her,
but when he proposes marriage, she
declares she will only marry the man
who can defeat her in battle. A fierce
battle ensues; Mahishasura is defeated.
He tries to elude the Goddess by changing his form several times, but she keeps
striking each one with her sword, finally
killing him by cutting off his head.