"I see a really depressed animal," she said.
"Forced to stand and cart around people, it's absolutely disgusting. Animal cruelty."
But as her cameraman continued to film the scene he soon caught the ire of one of the horse-carriage drivers.
"I hope you're not filming my child," the man asked.
"If you do, I'll beat you to death with your camera all right."
Peterson denied that they were filming his child.
"We're filming the animal slavery and exploitation," she replied
But the horse-carriage driver told her "I really don't care about you" as he walked off.
Peterson then proceeded to hurl a slew of insults at the driver and a group who got on his carriage as they rode away.
"Absolutely shameful, supporting slavery. Disgusting animal abuse," she shouted.
"Imagine paying for slavery for your own selfish pleasures. Absolutely disgusting.
"One day this will be a crime. Their suffering is on your hands.
"Animal abusers, total losers."
The animal rights activist quickly made an impression in Melbourne after staging a topless protest the day she arrived in the city.
She walked down the CBD's busy Bourke St with two other women on Wednesday last week to draw attention to the Australian wool industry.
Peterson has built an infamous reputation for staging similar incidents in Perth and across Australia, including targeting supermarkets, fast food outlets and football matches.