Teira Bennett and Eldea Teuira were 21 when they launched the "frenzied" attack on the convicted drug lord after a birthday party at Barwon Prison in February 2019.

"It sounds like they were making a statement," Victorian County Court Judge Liz Gaynor said about the attack.

"It's clearly arising from the newspaper articles ... this is a sort of marking of territory, a marking of status," she said.

The attack came the day after a front-page article called Mokbel a "prison big wig" and a "top enforcer" who disrupted an extortion racket run by Pacific Islanders in the prison.

Graphic footage aired in court on Friday showed the pair waiting for Mokbel before they launched their attack and accused him of talking to prison officers.

Bennett punches Mokbel's head and knocks him to the ground before Teuira pulls out a shiv and stabs the prone drug lord up to seven times in a "frenzied motion", crown prosecutor Kristie Churchill said.

Three improvised weapons known as shivs were made from sharpened wire and a fork were later found, covered in the two men's DNA.

After guards put Bennett on the ground, he yelled out: "well done cuss, G-Fam" and Teuira replied: "yeah, happy birthday bro".

Bennett also kicked Mokbel's head three times and used another shiv to attack him.

"You're not an enforcer, this is what you get for talking to the screws you f***ing dog," a prisoner officer heard Bennett yell.

Another officer heard Bennett say: "You think you're an enforcer, well you are f***ing not you c***".

Mokbel was left with severe injuries including displacement of the brain, skull fractures, black eyes, stab wounds and several lost teeth.

He was placed in an induced coma for five days and spent months in recovery.

Mokbel refused to give evidence against his attackers and neither gave any reason for what they did.

"It's all shrouded in secrecy on both sides," Judge Gaynor said.

Bennett and Teuira pleaded guilty to causing serious injury intentionally in circumstances of gross violence.

They also admitted causing reckless injury to another inmate stabbed during the attack, who came to Mokbel's aid.

Teuira's lawyer told the court his client was supported in court by his parents and other family.

He received "bad treatment" at the hands of older cousins when he visited the Cook Islands as a youngster, but details were not revealed in court.

The now-22-year-old had a lengthy criminal history and Judge Gaynor said there was a "pattern of entrenched, violent behaviour".

Bennett, 21, completed year 12 and had come from a good family with no prior convictions until he was jailed at 18, the court was told.

But he used up to 3.5 grams of ice per day prior to being sent to prison.

His lawyer said he had "the capacity to achieve some good things in his life" and was months away from being able to apply for parole when he attacked Mokbel.

Prosecutors argued they had no remorse, the community had to be protected and their prospects of rehabilitation were guarded.

The pair will next appear in court via videolink in February.

Australian Associated Press