Architect Bobby Halliday said Walker was a "neighbour from hell" who was responsible for the "worst three years of my life".
In the late 1980s, Halliday lived next to Walker in Blairlogie, near Stirling.
They shared a driveway but lived in separate properties.
In 1990, Walker wrote to Halliday to break some bad news: "Your free-range black hen has made its last foray into my garden.
"At 1.40pm today when I was exercising my dogs I spotted the hen on my banking up from my new wire net fencing. So did the dogs who ran down in pursuit.
"Unfortunately, on this occasion it didn't manage to get away and it was swiftly killed. Right now it is lying at the foot of my banking.
"I shall dispose of the body within the next 24 hours unless I hear from you."
Walker continued: "I fear for your cats. They roam around here regularly. Apart from the mess, one of these days one of them isn't going to be fast enough to get away."
In an interview with the Sunday Herald, Halliday said the cats were killed after the hen.
He said living next to Walker was a "nightmare" marked by constant tension.
Halliday recalled: "He walked past the house every morning and put two fingers up at us."
He continued: "The sickest thing was when my son was in the driveway.
"As he walked past my son, who was about five at the time, he patted him on the head and said 'We wouldn't want any harm to come to him, would we?'. It put shivers up my back."
Halliday also said Walker spied on him: "He told me that he had a telescope and used it to look in my dormer. He said he could see me watching EastEnders."
Luckily, Halliday said, Walker moved out after nearly three years of trouble.
He said Walker's new neighbours contacted him to say they were also having problems.
On learning about Walker's eventual success as a politician, he said: "I was reading the paper one day and I saw he was an MSP. I couldn't believe it."