Castellanos debuted as "El Salvaje" after being trained by Rey Misterio, Sr. and his brother, Fobia. He often teamed with Fobia and wore face paint. In March 1989, Castellanos began wrestling as "Psicosis" for the local promotion in his native Baja California, where some of his biggest feuds pitted him against El Hijo del Santo and Rey Mysterio Jr. He would eventually wrestle Mysterio Jr. over five hundred times throughout this career. He also frequently feuded with La Parka as well as Juventud Guerrera and Fuerza Guerrera.