He is currently signed to World Wrestling Entertainment ( WWE ) , wrestling on its Raw brand , where he is the World Heavyweight Champion . Jericho is also known for his appearances with World Championship Wrestling ( WCW ) and Extreme Championship Wrestling ( ECW ) and internationally in Canadian , Mexican and Japanese promotions . He is best known for his time in the World Wrestling Federation\/World Wrestling Entertainment ( WWF\/WWE ) , as well as in World Championship Wrestling ( WCW ) and Extreme Championship Wrestling ( ECW ) , and internationally in Canadian , Mexican and Japanese promotions .