In 1970, Chespirito needed a robust person to play Señor Barriga as well as Ñoño in his upcoming Televisa production of El Chavo del Ocho, and Vivar was hired for the job.

Both shows became major international hits, allowing Vivar to become known beyond Mexico and to tour all over Latin America, Spain and the United States.

He also made an attempt at becoming a telenovela actor, participating in his co-star Florinda Meza's production, Alguna vez Tendremos Alas.

He had a role in Guillermo del Toro's production of El Orfanato, filmed in Spain and released in October 2007. he would later voice Auguste Gusteau and Dug in the Latin American versions of Disney-Pixar's Ratatouille and Up (2009).

He would, however, reprise the voices of Señor Barriga and his son Ñoño for an episode of the animated adaptation of El Chavo, the only cast member from the original series to do so.