K'Kath

From Memory Alpha, the free Star Trek reference.

K'Kath was a hologram of an adolescent Klingon, who was friends with Jeffrey and Larg.

K'Kath was added to the doctor's holographic family program by B'Elanna Torres in an effort to make the picture-perfect family more real.

In this modified version, K'Kath, along with Larg, supplied Jeffrey with a Kut'luch with which the Human boy was supposed to kill an innocent person in order to prepare himself for his future life as a warrior. The Doctor did not approve of this ritual, and told the two Klingons to leave. He subsequently forbade his son to see either K'Kath or Larg and suggested that Jeffrey would find some nice Vulcan friends. (VOY: "Real Life")

K'Kath was played by Chad Haywood.