"He was the most beautiful, loving, happy, and perfect little baby we were so lucky to be gifted with. He was the light of our lives constantly filling our days with smiles and laughs. He leaves us with the best three months and 14 days of wonderful memories spent in this world.
"Zac, Mummy and Daddy love you very much, and always will.
"We want to thank everyone who has helped us, comforted us and grieved with us. Your kind words really mean the world to us. We ask you to keep us and Zara in your prayers."
Zachary’s injuries were so severe that he was rushed to the Royal Children’s Hospital in a police car, with The Age reporting that paramedics said there wasn’t time to wait for another ambulance. He died later that night.
Victorian Premier Daniel Andrews has announced that a memorial will be set up outside the GPO building in Bourke Street Mall to honour the victims of the attack, according to the ABC.
"We all need to come together and show our support for victims and family and for everybody who was caught up in this terrible, evil criminal act," he said.