Skanda, popularly known as Muruga, Kartik, Subrahmanya and Shanmugha, is the son of Shiva. But there are some legends that suggest that Skanda is the son of Agni. As per this legend Skanda is the son of Agni and Goddess Svaha.
Legend has it that Agni was enamored by the beauty of the seven wives of Sapta Rishis or the seven sages – Kashyapa, Atri, Bharadhvaja, Vishvamitra, Gauthama, Jamadagni and Vashishta.
Goddess Svaha was worried that Agni would end up doing something stupid and would end up getting cursed by the Rishis.
Goddess Savaha then took the form of the six wives of Saptarishis and made love to Agni, her husband. Skanda was born to Goddess Svaha after this incident.
It must be noted that in the story of Skanda as son of Shiva, it is Agni who carries the fiery semen of Shiva to Ganga who deposits in the forest and where Skanda is born as six babies looked after by Krittika Nakshatra. The six babies are later joined together by Goddess Parvati.
Thus in all stories associated with Skanda, the presence of Agni is there.