William's father choked back tears as he remembered his son, who was infatuated with the Spider-Man superhero.
"(He loved) anything that related to Spider-Man and superheroes," William's father said in the video.
"He's a cheeky, vibrant little boy ... full of energy. I mean he's my little boy."
But he said William was a cautious boy who wouldn't go with a stranger.
His mother said she had a vision that somebody "reached over ... has gone 'clump' on his shoulders, picked him up and moved him on ... because ... that's the only way ... to explain for him not to be there".
She said their family was struggling not knowing where William is or what happened to him.
"We need to know what happened to him ... 'cause we can't live forever ... like this."
She said she hoped whoever had him was looking after him.
"I want him to be safe, I want him to be feeling loved and I want someone to be looking after him because to imagine that something else is going on ... we can't live like that."
The parents are calling for any who has any information to contact Crime Stoppers immediately on 1800 333 000.
The release of the video comes more than a month since police scoured bushland in Bonny Hills, south of Port Macquarie, for evidence relating to William's whereabouts.
The three-day search was carried out near local washing machine repairman William "Bill" Spedding's home.
Mr Spedding was identified as a person of interest in the case after he was due to fix William's grandmother's washing machine around the time the toddler vanished.
However, Mr Spedding says he didn't go to the house on September 12 because he couldn't get in contact with William's grandmother.
Police searched the 63-year-old's home and business in nearby Laurieton in January, seizing various items, including cars, a mattress and computer, for forensic examination.
Mr Spedding has strongly denied any involvement and police have previously stressed he isn't their only line of inquiry.
-AAP