Hulk Hogan, who fought against him at Wrestlemania in 1985, told TMZ.com that Piper was his "best friend", adding, "He is a legend. God's gain is our loss. May his family in this time of need, find peace. Much love forever, HH."

Former World Wrestling Entertainment (WWE) star Bret 'The Hitman' Hart posted a photo of the pair on Facebook.com on Saturday (01Aug15), and wrote, "I can't find the words to describe the sorrow in my heart upon learning the news of my dear friend, Roddy Piper, passing away. He was my closest friend in the business, a man that schooled me and guided me throughout my career... I'm stunned and the hole in my heart will widen as it sinks in that I lost a brother of such great worth. What a tragic loss to all that knew him."

Vince MCMahon, CEO and chairman of WWE, tweeted on Friday, "Roddy Piper was one of the most entertaining, controversial and bombastic performers ever in WWE... beloved by millions of fans around the world. I extend my deepest condolences to his family."

Chris Jericho posted a photo on Instagram of the pair together, and wrote, "Sorry to hear of the passing of my friend and Wrestlemania rival #RoddyPiper. One of the greatest who ever lived, but more importantly a legit sweet family man with a good heart. God bless you Rod... See you on the other side. #RIPHotRod."

According to his agent, Piper, 61, suffered a cardiac arrest and died "peacefully in his sleep" at his home in Hollywood, California. He joined the WWE in 1984, and was inducted into the wrestling Hall of Fame in 2005.