Grant Kemp had consumed a "colossal" amount of alcohol before launching the unprovoked and vicious assault on the intoxicated and defenceless 56-year-old stranger at Ballarat Station early on April 5, 2019.

"Smashed that goose last night. Bam," Kemp told his girlfriend in a text.

"Just funny remembering that c***'s teeth coming out of his head."

Kemp, 36, was jailed by County Court Judge Gerard Mullaly on Monday for eight years after pleading guilty to intentionally causing serious injury.

He must serve five before becoming eligible for release on parole.

His victim has ongoing brain trauma and post-traumatic stress disorder symptoms.

"I'm scared of the future. I'm a totally changed man," he told the court in a statement.

He'd been drunk and toppled over at the station just before Kemp attacked.

"Although plainly too drunk for his own good he was uninjured," Judge Mullaly said.

"More importantly he was harmless."

Kemp was meant to be hopping on a bus to the airport, but went up to the man, stomped on his head and then kicked it hard.

"It was nothing short of a display of dangerous and sickening brutality," the judge said.

"What is inexplicable is the utter brutality of the stomp."

Kemp's victim now has a shuffling walk and slurred speech. He often feels dizzy, with blurred vision and headaches as well anxiety and panic attacks.

Kemp has schizophrenia and a drinking problem, as well as a history of cannabis and methamphetamine use.

He was hallucinating and paranoid at the time of the attack, but is doing better in custody with treatment.

In 2006, he was jailed in Tasmania for bashing a man unconscious.

Judge Mullaly said the previous six-year prison term did not seem to have deterred Kemp from serious violence.

His prospects for rehabilitation depended on maintaining mental health treatment and abstaining from alcohol, the judge added.

Kemp has already spent 479 days in custody.

Australian Associated Press