Robert McNab was sentenced to almost three years in jail for downloading indecent images of children, sharing them and sending offensive messages.
The 30-year-old admitted carrying out the offences between 2007 and 2016 at his flat in Greenock.
He was also given a two-year licence, which means he will be monitored after being released from prison.
Greenock Sheriff Court heard how McNab, who has previous convictions for hoarding indecent images of children and sexually assaulting a young girl, chatted to people on Facebook and WhatsApp using a fake name.
He talked about sexually abusing children and raping a baby.
The sex offender, who is also known as Robert Aitman, was found to have a stash of indecent pictures and videos - including footage of babies and children up to the age of 14 being sexually abused.
Defence solicitor Gerry Keenan said McNab was the victim of repeated sexual abuse when he was a child.
"Clearly there are issues which would require to be addressed in the public interest to minimise and reduce the risk of further offending," he said.
He asked for McNab to be spared jail and said he would engage with a treatment programme for sex offenders.
However, Sheriff Derek Hamilton ruled that a custodial sentence was required for such a "disturbing" case and jailed him for 35 months
He was also placed on the Sex Offenders Register for life.

The Scots lost their final warm-up Test 19-16 to France and Cotter believes the run-out in Paris will help his side in their World Cup opener against Japan.
"It certainly went up a level and was a very physical game against a very aggressive defence," he said.
"It was a big game with some pleasing things but things we need to work on."
Scotland went in 9-6 at the interval at the Stade de France thanks to the boot of Greig Laidlaw but lost momentum on occasions with problems at the set piece and losing line-out ball.
"We didn't get ball and when we did it wasn't clean," said Cotter who was in charge of Scotland for the 16th time.
"Despite that, I thought the players defended really well. The guys put in some big hits. Sometimes in days like that if you don't have the ball then you make up for it in other ways. That means you're adapting."
Cotter had special praise for John Hardie in the week the New Zealander picked his fellow countryman for Scotland's World Cup squad despite only having played an hour of rugby for the national side.
He said: "Crikey, John added an edge. He was very effective and got through an enormous amount of work.
"This sort of thing inspires people. He's a class player. We've got some class players and there are some class players that didn't make it."
Scotland's attention now turns to the World Cup and the opening match against Japan on 23 September, followed by games against the United States, South Africa and Samoa.
And, while acknowledging more work needs to be done, Cotter says there is a determination ahead of travelling to England for the finals.
"We're getting better," he said. "We got a reminder that we need to work on our line-out. I thought our scrum was better.
"I think we're showing agility on the field - both mental and physical. We're lining up for the arm wrestle, which is good.
"We're showing a little bit more explosiveness around the contact areas but we need to develop a bit more confidence. We want to do really well in this World Cup and the players are determined."

The Manchester Evening News reported it related to a councillor who admitted making indecent images of children.
Mike Owen and two senior officers have been suspended following an external review of the case, a spokeswoman said.
Council leader Rishi Shori said the suspensions would allow the three to "focus on responding" to the case.
He said they were "a neutral act".
The council had commissioned the review by childcare expert Malcolm Newsam after it "received allegations that there were failures to act appropriately in following safeguarding procedures in respect of an individual case," he added.
Deputy chief executive Pat Jones-Greenhalgh will replace Mr Owen until the council's own investigation is concluded, the authority's spokeswoman said.
A man has been jailed after he told a stranger that he wanted her to have a baby with her so he could abuse it.
[NEXT_CONCEPT]
Scotland head coach Vern Cotter says his team are "lining up for the arm wrestle" and are showing more "explosiveness" ahead of the World Cup.
[NEXT_CONCEPT]
Bury Council's chief executive has been suspended over claims he and others failed to follow procedures in their handling of a safeguarding case.