Alonzo is a minor antagonist featuring only in Prisoners of the Sun.
He is the sidekick of Rupac Inca Hucao, and is seen only on board the Pachacamac, the ship from which Professor Calculus is to be smuggled. Tintin sneaks onto the ship to rescue the Professor, only to be discovered by Hucao, Huaco calls Alonzo, and been knocked out by Tintin in which case he escapes. Alonzo is presumably Peruvian, of Spanish descent. His last name is unknown.