(I just found some stories regrading why shiva behead ganesha on Fb -by
Chinmay Naik on fb)
ut i need to share my research about ganeshji and elephant head . according to matsya, varuna,shiv mahapurana . mahadev went into tapsya and maa created a child from hridra(haldi lep) and wished that the child should be in born wise and need no more tapsya or stress to know inner life and so gauri nandan came into existance . after shivji returned from tap he saw the boy guarding kailas and found him to be extremly wise and shivji thought that he wud b the leader of 33 cr devta . but as child was demi god(half man half god) his human brain was limiting his power and only the brain of elephant can make him complete , scientifically elephant have the best memory in the world and at that same time mahadev remebered that indra cursed eravat to go to mritylok . but without any incident how can mahadev behead his child so he told mahamaya to create a leela that can give birth to such incident and the rest story u know . after beheading gauri nandan's head mahadev told gan pret to find the head of first animal and bring . eventually mahamaya brought the eravat to the ganpret and they brought his head freeding eravat and gauri nandan got hi complete ness . so guys i ve done lot of research on this so if possible please enter this in serial . there is also another less popular story in the Brahma Vaivarta Purana: Shiva asked Parvati to observe the punyaka vrata for a year to appease Vishnu in order to have a son. When a son was born to her, all the gods and goddesses assembled to rejoice on its birth. Lord Shani, the son of Surya (Sun-God), was also present but he refused to look at the infant. Perturbed at this behaviour, Parvati asked him the reason, and Shani replied that his looking at baby would harm the newborn. However, on Parvati's insistence when Shani eyed the baby, the child's head was severed instantly. All the gods started to bemoan, whereupon Vishnu hurried to the bank of river Pushpabhadra and brought back the head of a young elephant, and joined it to the baby's body, thus reviving it..