A violent and drunken mother starved her four-year-old son, force-fed him salt and locked him in a 'home-made prison' before beating him to death.
The toddler was so skinny he resembled a 'concentration camp victim' before he died from a head injury in March 2012.
The appalling cruelty of Magdalena Luczak, 27, and her partner Mariusz Krezolek, 33, of Coventry, was revealed to Birmingham Crown Court where they both deny murder.
Earlier, the jury heard that teachers at Little Heath Primary School watched from the staffroom as Daniel raided bins for apple cores and pear cores to eat. On one occasion, he took an empty tube of yoghurt from a bin in the classroom 'and was trying to get the last bit of yoghurt out', a teacher said.
This week, Daniel's biological father Eryk Pelka said he regularly found Daniel's mum drunk while looking after their son, and the pair would regularly argue - with her lashing out by hitting him over the face.
He told the court she once threatened to stab him with a knife at a party, and he had to call the police.
They met in Poland in 2004 then moved to Coventry a year later before Daniel was born. But their relationship deteriorated and he eventually left Britain to return to his native Poland when Daniel was aged one.
Speaking through a translator, he said: "They are only my thoughts but she was aggressive towards me. She was shouting and calling me names and she was trying to hit me as well."
Mr Pelka said at a party in 2007 police had to be called after Luczak threatened him with a knife.
He said: "We were at the party together and we had been drinking together. We were arguing all the time and she grabbed a knife.
"I rang the police and the police came and arrested both of us because I was drunk as well. I was pushing her away."
Mr Pelka, who worked as a lorry driver, told the court: "Daniel was a normal child, he was healthy and he was not neglected.
"Even his granny said, taking into consideration him drinking English milk, he was really chubby."
He said Daniel had never had any unusual eating patterns and had grown, and put on weight, normally.
During the four-week trial, Dr Karen McLachlan told the court she had been 'horrified' when she first saw Daniel's body at a mortuary on 5 March last year. He had weighed less than 24lb, which was 9lb less than he weighed in January 2011.
Mr Pelka told the court he had ended the relationship with Ms Luczak when he found out she had cheated on him.
Mr Krezolek and Ms Luczak have admitted child cruelty, but deny charges of murder and causing or allowing Daniel's death.
The trial continues.