Ixta

Ixta was an Aztec warrior in the 15th century and the son of Topau.

Ixta was Ian Chesterson's rival for command of the Aztec army. He nearly killed Ian when the First Doctor unknowingly gave him some cactus sap which slowed down Ian's reactions and sapped his strength. Barbara Wright, posing as Yetaxa stopped the fight just before Ixta made the final strike with his club by threatening Tlotoxl with a knife. He was killed by Ian in a battle on top of a tomb. Ian threw him off the tomb whilst buying time for the Doctor and the other companions to open the tomb door to the TARDIS. (TV: The Aztecs)

Behind the scenes
In the novelisation, he is Topau's grandson.

Ixta