Missing boy William Callaghan found

Missing boy William Callaghan was found on Wednesday. (Victoria Police)

A 14-year-old boy, who goes to school in Hamlyn Heights, has survived two nights in freezing bushland north of Melbourne before being found.

Hamlyn Views School student William Callaghan, who has non-verbal autism, went missing at Mount Disappointment about 2.20pm on Monday.

His disappearance sparked a massive search effort with hundreds of police, SES members and volunteers scouring the mountain for him.

Police had urged residents to play Thomas the Tank Engine music and put blankets, water, Vegemite, feta cheese and peanut butter outside their homes in bid to attract the boy.

About 11.55am on Wednesday, Reservoir man Ben Gibbs found William off a track in bushland, roughly 1.5 kilometres from an emergency command post.

“He was just about 15 metres from me, just standing there, he was really angelic just standing,” Mr Gibbs told the media.

“I heard that he liked Thomas the Tank and so I just sort of talked to him about Diesel and stuff like that. He didn’t seem bothered by me.”

William had no socks on, so Mr Gibbs gave him some socks, a jacket and chocolate, before carrying him to safety.

“He looked in reasonable health. He wasn’t shivering too bad.”

William’s “relieved” mum Penny Callaghan thanked Mr Gibbs and everyone who searched for her son as she addressed the media from inside an ambulance.

“More than anything, thank you everyone!” she called out.

“I’m so grateful, you’re all amazing! What an amazing community.”

William had used a communication app to tell his mum he felt “confused” and “scared”, and that his body felt weird following the ordeal, she said.

“He is well as could be under the circumstances, he is quite calm considering,” Ms Callaghan said.

“I can’t imagine what he’s been feeling and going through. I am just so relieved.”

His “first request was McDonalds”, she confirmed.

“He’s just a very special person and all the people in his life love him to bits.”

An ambulance later took William to the Royal Children’s Hospital.