Story of Mahodara Avatar:
The third incarnation or avatar of Lord Ganesha is known as Mahodara and Ganesha had reincarnated as Mahodara to defeat demon Mohasura.
The story is kind of confusing so as to understand what exactly was going on. Once Lord Shiva was engrossed in meditation for ages and was not displaying any signs of coming out of it. Meanwhile, the other Gods were in need of Lord Shiva and sought for assistance of Goddess Parvati in bringing Lord Shiva to a normal state. Goddess Parvati, therefore, assumed an alluring form and moved around Lord Shiva’s meditating spot. Due to this act of Goddess Parvati, Lord Shiva was brought back to normal wakeful consciousness. Parvati had to abandon the alluring “cover” and that abandoned energy later took the form of a demon and later Lord Ganesha had to reincarnate Himself to subdue it.
Lord Shiva and Goddess Parvati are the parents of Lord Ganesha. Hence, the psychological implication of this story will confuse anybody. Mohasur worshipped the sun God and attained the name of Daitya Raja, which means the king of all demons. Due to his powers, he soon started ruling all the three worlds. Such was his impact that all the Gods, and sages hid in the caves in the jungle in fear of him. During such a difficult time, the Sun God recommended to all other Gods that they should worship Mahodara who is none other than Lord Ganesha Himself. All the Gods and sages began doing penance in the name of Lord Ganesha. Ganesha was eventually pleased with their penance and assured them that He will take care of Mohasur and save the worlds from destruction. When Shukracharya heard this, he advised Mohasur to surrender before Mahodara or else the consequences will be very bad. Even Lord Vishnu suggested him the same that if he surrenders in front of Mahodara, he will not be killed or destroyed. That’s the reason he should accept the friendship of Mahodara wholeheartedly. After that, Lord Vishnu started singing praises of Mahodara and it kind of frightened Mohasura to a greater extent and he requested Vishnu to bring Mahodara with due respect and honor that His stature commands. When Mahodara arrived, Mohasura greeted Him with due respect and gratitude. He begged for forgiveness for his evil actions and started glorifying Lord Ganesha. Mohasura further promised the Gods that their swargaloka will be returned back to them and further also ensured them that he will always stay on the path of righteousness. He gave his words to the Gods and sages that from then onwards he would not try to harm anybody. After hearing all this, Mahodara was pleased and asked Mohasura to go back to pataal loka and never return again. All the Gods and sages were ecstatic and they started praising Lord Mahodara.