In "Peter's Got Woods", Glenn Quagmire reveals he has a son who lives in Madrid. He looks like Quagmire but, with a Spanish mustache, a striped shirt and a ponytail and he speaks Spanish and puts "Giggity" in between words. He was voiced by Seth MacFarlane.
In "Tales of a Third Grade Nothing", it is revealed Quagmire may have kids at Martin Mull Elementary, where he locates them in a Spanish class, a Special Education class, and Peter Griffin's third grade class. They say "Daddy?" every time Quagmire wanders in, except for the Spanish kid who says "Papa?" instead, much to his distress. He then goes to the teachers lounge, where he and another teacher decide to have unprotected sex.
When stopping at the Atlantic City Gentleman's Club in "Joe's Revenge", Peter inquires if Quagmire had ever been to Atlantic City before and he admitted he'd last been there about twenty years ago. A pair of twin strippers resembling Quagmire are seen giving a lap dance.
They look similar to a young Quagmire but resembling what class they are in. For instance in Peter's class a child looks just like Quagmire so when Quagmire comes in pretending to be Peter's dad Mrs. Wilson points out similarities to another child in her class, pointing to a mini-Quagmire. In special education it is a child with some type of special needs but with the face of Quagmire for the most part. In Spanish class it is a Hispanic version of a younger Quagmire.