Kal is the main antagonist of the first ever Doctor Who story "An Unearthly Child".
Kal was an outsider taken in by Za's tribe in the year 100,000 BC. At that time the tribe was undergoing a crisis. The previous leader had been killed before he passed on the secret of making fire to his son Za. As a result, Za's leadership of the tribe was in question and Kal hoped to take advantage of the situation. Kal saw his chance when he observed a group of strangers emerge from the Doctor's TARDIS, and later saw the group's leader, the First Doctor, produce fire by striking a match on a rock and breathing smoke through a pipe. Kal captured the Doctor and took him to the tribe, where he hoped to force the stranger to tell him the secret. The Old Mother helped the Doctor and his companions escape the Cave of Skulls into the forest. Kal killed the old woman in anger. When the strangers returned with Hur and an injured Za, the Doctor proved it was Kal who had killed Old Mother.
In anger, the tribe drove Kal into the darkness. Kal sneaked back, seeking revenge on the strangers and was confronted by Za. The two began to fight. During the fight, Kal was killed by Za. He was portrayed by Jeremy Young.
- Kal has the honor of appearing as the first-ever villain on Doctor Who.
- Though Kal himself does not appear until the second episode of "An Unearthly Child", "The Cave of Skulls", his shadow appears falling over the landscape during the last few seconds of the first episode, also called "An Unearthly Child".