He was chained to a cage in a room full of rats and snakes by his mum Rachel Trelfa, 31, and her lesbian partner Nyomi Fee, 29, who have today been convicted of killing the two-year-old boy.
During the trial, two other boys told the court of the catalogue of cruelty.
One of the seven-year-old boys was tied naked to a chair and left overnight in a room by Fee. He was forced to eat his own vomit and warned that a boa constrictor just feet away “ate naughty little boys”.
In a recording played to the High Court in Livingston, the boy said the 28-year-old showed him a drill-like device used for “chopping off willies”.
He also said Fee had showed him a sawing machine which she alleged she had used to kill his father.
Speaking about when he was allegedly left in a room full of rats and snakes in the couple’s home, the boy told cops: “She just told me ‘If anyone is naughty I’m just going to let it out and it’ll just eat yah.
“She tied me to the chair with the belt off a dressing gown so I couldn’t move my arms and I couldn’t get off the chair.
“It (the belt) was pink and fluffy. She left me there all night.”
The youngster detailed a catalogue of abuse he allegedly suffered at the hands of Trelfa and Fee – and gave a horrific account of being forced to eat his own vomit.
He said: “I’d been sick in a bowl and she (Fee) made me eat it all. My sick. I kept spitting it out as well. I kept being sick.
“She held up a jacket so she couldn’t see me.”
He also said the couple forced him to stand naked under freezing cold showers as punishment for wetting the bed.
The court heard the youngster once passed out when Fee pressed her foot on his throat as he lay on the floor.
He also described how he tried to escape from the house on three separate occasions but was caught and beaten.
Trefla and Fee blamed the youngster for Liam’s death – and at first the seven-year-old said he’d committed the crime.
But later he told cops he’d made it up.
The youngster told cops that on the day Liam died, Fee dragged him into the tot’s room and said: “Do you want to see what you’ve done to Liam?”
The child continued: “I said yes but I knew I hadn’t done anything. I think when I saw him he was dead.
“She got my hands and put them in his mouth. Nyomi said, “You’ve killed Liam.”
Social Work Scotland president Elaine Torrance said Liam’s death was “an absolute tragedy” after he suffered “deeply shocking” abuse.
Ms Torrance said: “What makes it worse is that the abuse was carried out by the very people Liam should have been able to trust the most: his mum and his step-mum.
“Cases like these are exceptional and children dying at the hands of their parents remains a rare occurrence in Scotland.
“Parents are the primary protectors of their children and when that relationship fails and where people go out of their way to keep agencies at arm’s length, children can be at terrible risk.”
Fife Council will continue with a significant case review to discover if more could have been done to help Liam, she added.