The deity mars has four arms. He has a hairy body. The small hairs of the body are red in colour. In his hands are mace and Trident and rest of the two hands are raised in the postures of bestowing fearlessness and blessings. He has a golden crown on his head and his vehicle is a lamb. He is attired in red coloured apparels and had red garlands in his neck.
In the 'Kalpa' of Varah' when Hiranyaksha, the elder brother of Hiranyakshipu had abducted the earth Lord Vishnu had taken incarnation as a boar and had rescued the earth by killing Hiranyaksha. Mother earth became very pleased after seeing lord Vishnu and had a desire to have him as her husband.
In his incarnation as a boar lord Vishnu's radiance was as dazzling illuminating and unbearable as crores of Suns. Lord Vishnu transformed his appearance into his enchanting form to fulfill the wish of the presiding deity of the earth and lived with earth for one year in aloofness. This way the birth of Mars took place (Brahmavaivarta Puran 2/8/29 to 43).