Huascar is a leading member of the Incas in Prisoners of the Sun.
He observes the actions of Tintin and Captain Haddock when they arrive in Peru in an attempt to rescue their kidnapped friend Professor Calculus. He listens in on their conversation with the police chief and follows them through the streets of Callao. At Santa Clara, he arranges a train car to be released that nearly killed Tintin, by threatening a guard with the consequences of disobeying the orders of the Incan preisthood.
At Jauga, however, he sees Tintin aiding a young local orange seller named Zorrino from Pedro and Pedro. Surprised that a white foreigner could preform such a selfless act, he advises Tintin to stop searching for Calculus as he will be likely risking his life in so doing. Tintin tells him he will continue regardless, so Huascar gives him a talisman that he claims will keep danger away.
Later after being captured by the Incas, Tintin gives the talisman to Zorrino who presents it to the Incas, who intend to kill him for treachery. The talisman forces them to spare the young boy's life. Present at the scene, Huascar is revealed to be a High Priest of the Sun who later uses a large magnifying glass to set fire to the stake used to burn the Westerners but is thwarted by an eclipse, which leads to their eventual release and atonement.