An illegal poacher caught with Australia's largest-ever haul of animal skulls and bones will spend more than a year in jail for his "morbid obsession".

Key points: Indian national Keerthi Eswaran was sentenced to 23 months in prison

Indian national Keerthi Eswaran was sentenced to 23 months in prison He had reoffended after pleading guilty in 2017 to possessing and selling Australia's largest ever haul of animal parts

He had reoffended after pleading guilty in 2017 to possessing and selling Australia's largest ever haul of animal parts He sold crocodile and wombat skulls, baboons, chipmunk tails, a king colobus monkey skull, ocelot, and had more than 600 listings on eBay valued at almost $70,000 when he was raided by police

Indian national Keerthi Eswaran, 35, was sentenced in Darwin's Supreme Court on Friday after pleading guilty to eight fresh charges.

He had reoffended just shy of five months into a suspended sentence for possessing the animal parts, after pleading guilty in March 2017 to an Australian record of more than 350 charges relating to the sale and possession of animals, some threatened and endangered.

Then, he had been handed a 10-month sentence, fully suspended, which crown prosecutor Ian Rowbottom argued did nothing to deter him.

He sold crocodile and wombat skulls, baboons, chipmunk tails, a king colobus monkey skull, even an ocelot, and had more than 600 listings on eBay valued at almost $70,000 when his Palmerston home was raided by police, finding animal parts in freezers and rotting away in buckets.

He was caught while trying to post a baboon skull to the US as well as trying to post wedge-tailed eagle feet, and magpie goose and ibis skulls.

His collection was "a morbid obsession," Mr Rowbottom told the court.

Convicted poacher Keerthi Eswaran after pleading guilty to wildlife offences in the NT Supreme Court. ( ABC News: Kristy O'Brien )

On Friday, Eswaran pleaded guilty to charges related to removing protected wildlife, such as the skull of an orange-footed scrub fowl from the Northern Territory, and possessing Chinese freshwater turtle skulls.

Mr Rowbottom argued the previous sentence was "certainly very merciful" but was imposed wrongly under the belief that Eswaran was a wildlife lover who volunteered at animal shelters and wanted to work for Parks NT.

He said Eswaran was running a commercial enterprise, earning $2,500 per month as a taxidermist.

"It wasn't like he was selling ivory," defence lawyer Peter Maley said.

He had previously told the court Eswaran was catering to a decorative skull market where people liked to display the skulls in their homes.

The former crocodile-park taxidermist maintained most of his work had been in stuffing cats, dogs and cane toads that people had become attached to.

Skulls and bones found by rangers included a red-tailed black cockatoo, wombats and monkeys. ( Supplied: Parks and Wildlife )

In his sentencing remarks, Justice Peter Barr said any conservationist would take offence at the accused's behaviour towards animals.

"While there's no suggestion you killed any of these animals, your conduct may encourage other people to hunt these species on the black market," Justice Barr said.

Mr Eswaran was sentenced to 23 months in prison — his prior full suspended sentence plus 13 months for the fresh charges — and he will be eligible for parole in June 2020.

The maximum sentence was 10 years' imprisonment.

Eswaran plans to return to India to be with his wife and children once he has served his sentence.

"This sentence sends a strong message to people who involve themselves in illegal wildlife trade and trafficking, and reflects the value Territorians place on our unique protected species, that people cannot simply take as they please for commercial gain," said acting director of wildlife Peter Ross.