A Buddhist deity and a bodhisattva, Marichi is seen as a remover of darkness, obstacles and evil, as symbolised in her association with light, the sun and various weapons. She has been commonly depicted as a tantric protector deity and Goddess of the Dawn among Buddhist cultures in India, China and Tibet, and as far as Korea, Mongolia and Thailand. She is invoked in Tibet at sunrise as a spiritual destroyer of darkness, and for protection. In Japan, where she is revered as a protective figure for warriors, she is worshipped as Marishiten. Represented in diverse forms over time and across regions — from a two-armed attendant to the saviour deity Tara, to an independent warrior deity with many heads and arms — Marichi images are distinguished by the motif of the boar or sow, appearing as one of her faces or as her vehicle.

She is most commonly depicted holding an ashoka branch, a vajra, a needle and thread — the latter functioning as a weapon to sew closed the eyes and mouths of evildoers. In various depictions she also holds a bow and arrow, sword, noose, elephant goad and mace, among other implements. As the bringer of light, she is also shown holding the Sun in one or more hands. She may take a placid form with a single face and two arms, or be depicted with three or more faces — including a placid, a wrathful and a boar-face — and up to twelve arms, reminiscent of Hindu goddesses Durga and Varahi. She is typically depicted in a dynamic standing pose with her legs wide apart in the heroic or militant pratyalidha pose — the right leg bent and left leg outstretched. One of her hands takes the threatening tarjani mudra. She is commonly presented with yellow or red skin, and rarely white-complexioned. In other depictions similar to those of the Hindu Sun god, she is shown in a chariot with seven boars or sows as her steeds (instead of horses); occasionally she is seated on a lotus atop a single sow. In rare instances Marichi is represented in zoomorphic form as a sow. 

While scholars are unable to attribute a singular origin to the goddess, she is variously thought to have evolved from nature spirits, Vedic solar gods such as Surya and Ushas, the Iranian solar deity cult related to Mithra, or the cult of martial goddesses that includes Chandi, Devi and Shakti, worshipped in India from the fifth century onwards. The earliest images found of Marichi are relief sculptures that date to the first and second century BCE. Steles that depict the goddess resembling a yakshi or a benign tree-spirit have been found in the important Buddhist sites of Bharhut, Sanchi and Nagarjunakonda. Here she is seen holding an ashoka twig in one hand and a sword or noose in the other. 

Descriptions of Marichi are found in Sanskrit philosophical texts, and sutras such as the Vedas and the Bhagavad Gita. The Sadhanamala, a seminal Buddhist instructional manual on meditation compiled between the fifth and twelfth centuries CE, describes six distinct forms of Marichi, with varying numbers of heads and arms — one, three, five or six heads, and two, eight, ten or twelve arms. In artwork from twelfth-century illustrated manuscripts from southern Bengal (parts of present-day Bangladesh and West Bengal) Marichi is depicted with yellow skin and three eyes. She appears first as a two-armed deity and later as a more fierce three-faced, eight-armed one with a tall crown, facing Tara. In both illustrations, she stands in a pratyalidha lunge bearing an ashoka twig and a vajra, against a flaming orb that functions as a full-body halo. These elements comprise some of the most prevalent in Marichi iconography.