The proper spelling is "kris" with one "s". It's a traditional sword or dagger from the area of Indonesia and Southeast Asia, often seen with a "wavy" blade (as opposed to a straight-edged blade). That is, the edges of the blade are in sinuous curves rather like a sine wave. This makes the kris look particularly vicious. I remember seeing them in the wonderful adventure comic, Jungle Jim, back in the 1950s and early 60s. Jungle Jim Bradley and his faithful Malay sidekick, Kolu, often found themselves up against marauding gangs of Malay pirates armed with kris, musket, and a variety of more modern weapons on some occasions. It was the glorious British Commonwealth (Pip, pip and Hurrah, boys!) against the ungodly Communists and the river pirates. Think Indiana Jones wearing a pith helmet...and Kolu in place of Tonto. Marvelously exotic stuff! :)