He began his Muppet association on Plaza Sésamo, first dubbing Herry Monster (Greñaldo) and other monsters. By the time of The Muppet Show (El show de los Muppets), Iglesias was cast as Kermit and took over the role on the Plaza as well (from original voice Salvador Nájar), continuing into the movie dubs. He served as dubbing director for the original Mexican dub of The Dark Crystal.
Oustide of Kermit, Iglesias' dubbing career was highlighted by Starsky & Hutch (dubbing Paul Michael Glaser as Starsky), as well as Davy Jones on The Monkees, Fred Grandy on The Love Boat, and Gary Burghoff on M*A*S*H. Animation roles included Scrappy-Doo, Jimmy Olsen on Filmation's Superman, and many characters on The Simpsons (including Sideshow Mel, Snake, and the coyote originally voiced by Johnny Cash). Iglesias died in the late 2000s.