Police allege the 38-year-old man had become one of the nation's biggest self-producers of online bestiality content by the time officers arrested him this week.
He came to their attention in February during raids across the greater Sydney area targeting the online sharing and promotion of child abuse material.
Further inquiries into the persona "Beast Boy" revealed the person was using encrypted messaging apps to allegedly share bestiality material.
It featured the sexual abuse of various animals such as dogs, sheep, goats, chickens and a dead kangaroo.
Satisfied they'd uncovered Beast Boy's real identity, detectives arrested the 38-year-old man at a property in Moorland on the NSW mid-north coast on Tuesday.
A dog at the property was seized by RSPCA NSW inspectors, having been identified as one of the animals allegedly abused in the material shared online.
The man faced Taree Local Court on Wednesday on 20 charges including eight counts of bestiality.
He was refused bail and was remanded ahead of a July 8 court mention.
More charges are expected.
The offence of bestiality carries up to 14 years in jail in NSW.