Karthigai, Krittika, or Kartika is the third of the 27 birth stars of the lunar zodiac. The story of Muruga or Kartikeya is closely associated with Krittika.
Legend has it that when Muruga, the commander in chief and son of Shiva, was born, the Devas deputed six mothers called Krittikas to breast-feed him. As per Mahabharata, after having fed Muruga, the mothers entered into the sphere of stars and hence this group of stars is called Krittika or Karthigai.
Muruga gets the name Kartikeya from his these six mothers.
As per some Puranas, Krittika is also the daughter of Daksha Prajapati.