A demon named Soorapadan was threatening the Rishies and all the good people on the earth, they prayed Shiva for help. Shiva produces six sparks and asked god Agni (fire) and Vayu (wind) to carry them to river Ganga. They Carried the Sparks to ganga and landed these 6 sparks in the Lap of Goddess Ganga.
Ganga brought them to Sharavana forest, those 6 sparks turned into 6 babies , looked after by 6 Nymphs Known as Kritikas. Parvati comes and Hugs all 6 children , and they unites into one child with six head and 12 hands. Parvati wonders how will she take care of a son with 6 heads and 12 hands , then Kathikeya turned himself into a mortal boy. Shiva also declared him as his son and blessed him 6 several names.
Kathikeya have sevral names:
1. Kathikeya : son of Kritikas
2. Skanda : son of Parvati
3. Sharavana : son of forest (Sharavana, where he was born)
4. Kumara : son of Ganga
5. Mahasena : son of Agni
6. Guha : son of Shiva
Karthikeya Killed Soorapadan and saved goodness.
Karthikeya rides peacock