The blade of a keris is made of metal and usually wavy, although there are some keris with non-wavy blade. The wavy blade is a refence to giant snake called naga. The waves (called luk), are always odd numbered. The blade of a high quality keris is usually made from high quality metal and some said that the metal came from a meteorite, and is very intricately decorated. The handle and the sheath are usually made from wood and sometimes adorned wih metal as decoration.
A keris is often said to have supernatural power and is considered to be alive because it is believed that a keris has a spirit in side it. That is why a keris usually has a name and in certain dates the owner of the keris has to do rituals to soothe the spirit. It is said that a powerful keris can stand up on its tip if its name is called by its owner.
In wearing traditional costume, especially formal Javanese traditional costume for a formal event, a keris is an important element and usually worn at the back. In marriage ceremony, a keris should be adorned with jasmine flower as a symbol that a man should not easily be angry, cruel, fierce, too aggressive, tyrannical and abusive.
- Keris of Mpu Gandring is the famous cursed keris in the story The Legend of the Keris of Mpu Gandring made by famous keris maker Mpu Gandring, who was killed by his own creation. The keris would later taken five more lives.
- Keris Setan Kober (Devil of the Grave Keris), which was owned by Arya Penangsang, the powerful lord of Jipang district of ancient Java. it was said that when finishing the keris, the keris maker, Mpu Bayu Aji, tried infuse spiritual power to the keris but was disturbed by a crying devil in a nearby cemetary, hence the name Devil of the Grave Keris. As the result, although powerful, the kris is defective. Since Mpu Bayu Aji is too ambitious to create a powerful weapon, plus the disturbance from the devil, the kris have temperamental evil nature that cause the wielder to be overtly ambitious and impatient. The keris is featured in the Legend of Jaka Tingkir, in which Arya Penangsang was Jaka Tingkir's only equal rival.