Fischbacher, 68, and Horn, 63, will perform at the Lou Ruvo Brain Institute's "Keep Memory Alive" fundraiser at a location yet to be confirmed. This year, tickets to the charity dinner cost $1,500; the event raised more than $12 million.
Horn was critically injured when the white tiger, Montecore, sank its teeth into his neck and dragged him offstage in front of a horrified audience at The Mirage in October 2003, ending one of the most successful casino shows in Las Vegas history.
The pair have said they believed Montecore sensed Horn was having a ministroke and was dragging him to safety, rather than attacking him.
Publicist Dave Kirvin said Monday the German-born duo are working out plans for the act, adding that he would be "very surprised if animals were not part of the performance."
"Siegfried and Roy and white lions and other endangered animals go hand in hand," he said.
The Lou Ruvo Brain Institute, designed by architect Frank Gehry, is set to open in downtown Las Vegas next year.
