Oswaldo Castillo is a Nicaraguan American gardener/construction worker-turned-actor.
Castillo was born in Nicaragua and, in 1986, fled to the United States after being tortured by Somoza militants for suspected opposition activities.  He settled in Los Angeles, California and worked in construction, where he later met Adam Carolla, his good friend, in 1989.
Castillo is the co-star of The Hammer. He plays "Oz", a character which is based on his real life while working in construction with Adam Carolla. Castillo and Carolla met while working in construction together and building the Bodies in Motion gym in Pasadena, where they shot the movie. Castillo continued as Carrolla's gardener and was asked to appear in Carrolla's independent film, The Hammer, to play a character based on himself.
He also appeared as a castmember on the The Adam Carolla Project working with Adam Carolla as a member of a construction crew.
Castillo is currently a movie reviewer and singer on The Adam Carolla Show.