Harper became a free agent on Feb. 13 when the Saints released him after eight seasons.
"It will be an easy transition," Harper said. "I'm very excited about the opportunity to be here and help this team to continue to progress the way they have the last couple of years.
"Growing up, I loved the Panthers. My first jersey was a Tim Biakabutuka jersey. The colors are good. I look good in black."
A second-round draft pick by the Saints in 2006 from Alabama, Harper made the Pro Bowl in 2009 and 2010. He posted five consecutive 100-tackle seasons beginning in 2008, a streak that ended last season when a knee injury limited him to nine games and 41 tackles.
But Harper ended the season healthy, playing in the last seven regular season games and starting both of the Saints' postseason games. The 31-year-old has been durable throughout his career. Since playing in just five games as a rookie, Harper missed just two games over the next six seasons before last year's injury.
"I started the last few games and played well," Harper said. "When I'm healthy, I play at extremely high level. I know I can still do that."
Renowned as a sure tackler and hard hitter, Harper has 742 career tackles, averaging 111.5 tackles over his six full seasons. He also has 17 sacks, 13 forced fumbles, seven interceptions and 53 passes defensed.
"I've been fairly decent my whole career at flying around and trying to make tackles and making big plays when they come to me," Harper said.
"Playing with a front seven like this is going to make it a lot easier to go out there and play at a high level. The front seven is amazing, with linebackers like
Harper played strong safety for New Orleans. Veteran Panthers safety
"I know it's a great fit for me and my skill set to help this defense that doesn't need a lot of help," Harper said. "I'm not here to change anything or take over this team – I'm just here to add to it."