Mukasura or Mukāsura was an asura

Asura

-In Hinduism:In Hinduism, the Asuras constitute a group of power-seeking deities, sometimes considered sinful and materialistic. The Daityas and Danavas were combinedly known as Asuras. The Asura were opposed to the Devas. Both groups are children of Kasyapa...

in the Indian epic Mahabharata

Mahabharata

The Mahabharata is one of the two major Sanskrit epics of ancient India and Nepal, the other being the Ramayana. The epic is part of itihasa....

. He was a friend of the Kauravas and the son of Upasunda

Upasunda

A mythological character from the great epic Mahabharata, Upasunda was an asura prince and the brother of Sunda. The brothers grew up to be very powerful and were always of one mind. Together, they embarked on a campaign of world domination that began with a program of extreme asceticism in the...

, who was sent to disturb the austerities

Tapas (Sanskrit)

Tapasya in Sanskrit means "heat". In Vedic religion and Hinduism, it is used figuratively, denoting spiritual suffering, mortification or austerity, and also the spiritual ecstasy of a yogin or tāpasá . In the Rigveda, the word is connected with the Soma cult...

 that Arjuna

Arjuna

Arjuna in Indian mythology is the greatest warrior on earth and is one of the Pandavas, the heroes of the Hindu epic Mahābhārata. Arjuna, whose name means 'bright', 'shining', 'white' or 'silver' Arjuna (Devanagari: अर्जुन, Thai: อรชุน, Orachun, Tamil: Arjunan, Indonesian and Javanese: Harjuna,...

 was performing at Indra keeladri, geographically now in Andhra pradesh

Andhra Pradesh

Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...

. Mukasura went to the forest where Arjuna was practicing his vows of prayer, vigil

Vigil

A vigil is a period of purposeful sleeplessness, an occasion for devotional watching, or an observance...

, and fast and attacked Arjuna in the form of a boar.

Arjuna was actually conducting his penance to please Siva

Shiva

Shiva is a major Hindu deity, and is the destroyer god or transformer among the Trimurti, the Hindu Trinity of the primary aspects of the divine. God Shiva is a yogi who has notice of everything that happens in the world and is the main aspect of life. Yet one with great power lives a life of a...

 and obtain the great weapon called pasupatha-astra (the missile of pasupatha, the lord of the animate world). Lord Siva sends Mukasara in the form of a boar to test the severity of Arjuna's penances. He follows the boar in the guise of a hunter.

Arjuna gets angry at the disturbing beast and shoots an arrow, while Siva simultaneously pierces it with an arrow of his own. A big argument over who has killed the boar follows, and a great fight ensues between Arjuna and Lord siva.

In the end, Siva appreciates the valour of Arjuna and grants hims the boon of the missile.

Kiratarjuneeyam

Kirātārjunīya

Kirātārjunīya is a Sanskrit kavya by Bhāravi, written in the 6th century or earlier. It is an epic poem in eighteen cantos describing the combat between Arjuna and lord Shiva in the guise of a kirāta or mountain-dwelling hunter. Along with the Naiṣadhacarita and the Shishupala Vadha, it is one of...

 of Bharavi

Bharavi

Bharavi was a Sanskrit poet known for his Mahakavya , the Kirātārjunīya in 18 cantos based on an episode from the Mahabharata.-Time and place:...

 and a Telugu

Telugu language

Telugu is a Central Dravidian language primarily spoken in the state of Andhra Pradesh, India, where it is an official language. It is also spoken in the neighbouring states of Chattisgarh, Karnataka, Maharashtra, Orissa and Tamil Nadu...

kavyam with the same name has the same storyline.