Background & Story
Jaguar Javier is a great warrior who was trained by Uay Chivo in the Forest Del Chivo hundreds of years before the events of Guacamelee!. When Carlos Calaca arrived on the scene and threatened to kill the old master, Javier swore fealty to him instead, thus saving Uay Chivo's life. Javier, meanwhile, was trapped in an eternity of servitude and transformed into a half-man, half-jaguar.
Although he is ultimately just another of Carlos Calaca's henchman, Javier is more a rival of Juan's than a true villain, and he never appears alongside any of the henchmen, or Calaca. He is the only boss enemy who only appears alone and never makes reference to the kidnapped love interest or Juan's struggle to rescue her.
When Jaguar Javier is first encountered atop the Forest's bridge, he tries to spare Juan and suggests he simply return home - when Juan refuses, Javier topples the bridge and leaves him (he thinks) for dead. Before Juan reaches the summit of Sierra Morena and the two have a rematch he will have received all of the ability upgrades from Jaguar's former master, Uay Chivo.
Atop Sierra Morena - near the very end of Juan's adventure - Javier expresses surprise in seeing the luchador come so far, and notes that it's been centuries since he faced a worthy opponent. "May the best man win!" he says. Unlike the other boss fight in the game there are no extraneous elements present: there are no extra enemies, no environmental damage, no platforms or 1-hit kills - just Javier and Juan in a slug fest. Once defeated, he extols Juan's abilities, and regrets his own cowardice and failure to face Calaca all those years ago.
"Just when I had lost all faith in humanity and resigned myself to the coming age of the dead, I see that hope, love and perseverance still burn within your kind."Jaguar Javier
An update to the game in February 2015 added 4-player co-op play, and Jaguar Javier is one of the playable characters. While the mechanical inputs are identical to Juan's, Javier has many of his trademark moves that he uses against you in battle, and some new ones as well.