A Banksia Grove man has pleaded guilty to animal cruelty after he was involved in the torture and killing of a kangaroo using knuckle dusters and a firearm.

Warning: This story contains content that may be distressing for some readers.

Dylan Leslie Griffin, 22, was one of four men charged in September with using a number of weapons to fatally torture two kangaroos in May and June.

The men were charged after police seized videos described by senior detectives as among the most disturbing things and worst acts of animal cruelty they had ever seen.

In the first incident on May 19, a kangaroo was burnt, shot with a firearm and kicked before being held by a man and punched a number of times with knuckle dusters.

Police said Griffin shot the kangaroo in the eye while others held it down.

Appearing in Joondalup Magistrates Court, Griffin pleaded guilty before the case was adjourned, with sentencing set to take place in January.

Police released images of the men after seizing videos of kangaroos being tortured. ( Supplied: WA Police )

He faces a potential jail term of up to five years, with police prosecutors indicating that was something they would suggest the court considered.

Griffin was released on bail on the condition that his father, who is a retired member of the Outlaws motorcycle gang, post $2,000 surety.

Detectives discovered two videos, as well as a Snapchat video and a number of photographs, after seizing a mobile phone during another investigation in September.

Griffin's co-accused include 28-year-old Ricky Ian Swan from Aveley, 26-year-old Ben Jaydon Malpuss from Woodvale and 26-year-old Luke Kevin Dempster from Wanneroo.

Swan also pleaded guilty in October to animal cruelty and possession of a knife and was released on bail, to be sentenced later this month.

All of the men have alleged links to outlaw motorcycle gang the Outlaws.

The ABC has decided not to publish heavily blurred versions of the kangaroo torture footage released by police.