Kardiak is a villain from the Teen Titans show. He is an artificial entity that resembles a heart and is an enemy of the Teen Titans.
Kardiak first fought the Teen Titans when he tried to kidnap a young boy from a playground. His kipnapping failed and he was defeated by Raven, who used her power to rip him apart. Kardiak managed to rebuild himself and undertook another attempt at kidnapping a kid. This time he succeeded in kidnapping a little girl from her bedroom. Raven defeats him again by using magic she learned from Malchior and tried to consume both Kardiak and the child with the magic. Beast boy managed to interrupt the magic and saves the girl. it is unknown what happens to Kardiak after the incident.
Kardiak was then recruited by the Brotherhood of Evil. He was sent to capture Beast Boy but was defeated. At the final battle at the Brotherhood's base, Kardiak was once again defeated and ended up flash-frozen with the rest of the villains.
Kardiak's power includes the power to fly, to heal himself and to suck up enemies with his tentacles.