The older boy, aged nine, is in a serious but stable condition at the Royal Childrens' Hospital in Melbourne after he allegedly escaped from his mother but was "savagely mauled" by a dog.
The Brisbane man has claimed he is "not in a situation" to be able to afford to get from Queensland to New South Wales and has asked for a total of $5000 to fund his travel costs.
But the father has received a huge amount of backlash for having the nerve to crowdfund money, after admitting he had not seen the eldest boy for almost six years and never met the youngest, splitting from their mother before he was born.
"What hurts most is I've never met (the youngest). Now I'll never meet him," he wrote online, according to The Herald Sun.
"I don't want to bury him, he's meant to bury me."
One commenter on the GoFundMe page labelled the man a "disgrace as a father".
"I wouldn't donate my toenail clippings to you. You didn't bother about ever seeing your son in the time he was alive and now you need $5000 to go and say goodbye to him," she wrote.
"That dear little boy needed a dad when he was alive... Give respect to your son and stay away from his funeral and as for your son in hospital how often did you see him? Obviously not in the time your baby was alive. You are a disgrace as a father."
Another woman called him "despicable".
"You may be called other names, but father is not one of them. These two boys weren't even acknowledged by you until they made the headlines. You are a despicable human being."
Others have suggested he donate the money to the boys' grandmother, who cared for her grandchildren them for the past 18 months before they were allegedly snatched from her Deniliquin home by the mother.
The Red Heart Campaign, a platform for survivors of domestic violence and familial child abuse, has also taken to its Facebook page to encourage people to think twice before donating.
"It does not cost $5000 to fly anywhere in Australia, we know the little lad's funeral will be covered by the State Government funeral fund or Share The Dignity's Because We Care program, the father has not indicated that this money will be used to support the victim's brother, he acknowledges he has no relationship with the children and we'd feel more comfortable if the people behind the Fund are the children's legal guardians," the organisation wrote.
"We encourage everyone to think twice before donating."
The mother, 27, was charged with attempted murder of her eldest son on Thursday. A court heard on Friday she "had to drown my babies".
NSW police confirmed on Saturday, after the younger boy's body was found, the mother would also face a murder charge.
The GoFundMe page has received $850 in donations so far.
"All funds raised will go toward getting me to my older son with all remaining funds going toward burying my little boy," he said.
