The 'Project Runway' mentor has compared American VOGUE's notorious Editor-in-Chief to mythical figure Medusa, who is capable of turning people to stone just by looking at them.
He joked to the New York Post's Page Six: ''I don't look her in the eyes, because I will be turned into stone.''
The pair have had a frosty relationship ever since Tim wrote in his 2010 book 'Gunn's Golden Rules' that Anna asked to be carried out of a New York fashion show instead of riding in a public elevator.
Tim wrote: ''We ran over to [an] elevator bay to see if Anna would deign to get on. Then...what did we see but Anna being carried down the stairs...bodyguards had made a fireman's lock and were racing her from landing to landing.''
The flamboyant star was then hit with complaints from the fashion maven's spokespeople, demanding he retract the statement.
He said: ''All hell broke loose... Her office was insisting I print a retraction.''
However, Tim insists he has no hard feelings towards Anna and wasn't making a comment about her character.
The 60-year-old star explained at the time: ''I wasn't maligning her character,'' he said. ''I was simply making a statement of facts. It didn't say anything about her as a person.''
Was the singer unknowingly taking counterfeit pain medication?
Roberts had left the band in 2012, due to problems with blood circulation and other health issues.
The popstar turned actress is back in the studio.