Przemyslaw Kaluzny was previously a member of a Polish criminal gang that stole vehicles to order before moving to Scotland a year before his crazed attack, a court heard.
Dundee Sheriff Court was told Kaluzny has served a series of jail terms in Poland for violent offences, including a four-and-a-half year sentence for robbery and ten months for hostage-taking.
His frenzied Easter Sunday rampage was captured in a CCTV video, which was shown to the court yesterday.
The court heard that Kaluzny took class A ecstasy that he found in a Kinder Egg on the street before entering the store.
He first stripped off as he walked through the store before picking up a terrified six-year-old boy who was on an Easter day out with his father and grandmother.
Footage played in court showed shoppers walking past as Kaluzny strolled through the store completely naked.
He then grabbed the boy and dragged him along the ground as he was chased by shoppers and staff.
One worker repeatedly rammed Kaluzny with a trolley before the boy’s grandmother, who cannot be named to protect the boy’s identity, hit him with her handbag. Staff and shoppers then dived on top of Kaluzny as he tried to struggle free.
Fiscal depute Eilidh Robertson told the court that two hours before the incident Kaluzny had gone to a neighbour’s home where he “did not appear himself” and took ecstasy before leaving in a car for the shop.
Kaluzny, 41, presently detained at Murray Royal Hospital in Perth, pleaded guilty on indictment to possessing an offensive weapon, behaving in a threatening and abusive manner, public indecency, abduction, assault, assault to injury and vandalism.
Defence solicitor Nicola Brown said: “He was part of a ring of heavy duty criminals at home who in effect stole vehicles to order and that’s why his previous sentences have been fairly lengthy.
“He came to this country in April 2014 to support a friend but became disillusioned. He took green tablets he had found in a Kinder Egg on the street in a suicide bid before this happened.”
Sheriff Lorna Drummond QC deferred sentence.