And probably, a new Ganesh is in the area. Ganesh?
Yep, him with the elephant head. You know the story. Parvati is having her bath, Shiva has been tempted down off the mountain and he is keen to see her. Their son, who Shiva doesn’t recognise (he’s been away meditating – as one does), is guarding his mum’s door – but the overeagre Shiva storms in and lops off the boys head with his sword when he tries to prevent entry to the washrooms. Parvati is, to say the least, annoyed, and she insists Shiva repair the mess he’s made. The God, I guess in a bit of a hurry to get on with it, sends out an aide to find the first head that would serve as a replacement. Unfortunately, its a quiet day and the only creature that the aide can find is an elephant. Parvati is spitting chips unless the situation is put to rights, so Shiva agrees this elephant head will have to do. Hence, Ganesh, the elephant-headed god is (re)born [the prognosis for our elephant was of course not so good before this recent auspicious intervention, see here].
Ganesh is a useful god – he’s a patron saint of sorts for students. The reason being a great story – when Valmiki was telling the tale of the Mahabharata he said he’d only tell it once and only if there was a scribe who could take it all down in a sitting (its 100,000 verses or so, and can be twisted to all manner of ideological ends). For such a daunting task only the memory-enhanced son of Shiva could be considered for the job. But even he got into trouble when his pencil failed part way through. Not to worry, he broke off one of his tusks and carried on writing. Brilliant. And this dedication is maybe why there are campaigns to ban trade in ivory. [strangely, reported by the Jehovah's here]
You can read the rest of the story in many places, but to get a really good take on it, including the ways the Ganesh story has been used by the hindu right etc., check out comrade Raminder Kaur’s excellent book on the Ganapati festivals of Western India.