This grandson of child actor Jackie Coogan made his first appearance on TV at age one-and-a-half when he walked on stage and hugged his grandfather on "This Is Your Life. " Short, blond and stocky, Keith Coogan carved a niche for himself playing flakes, energetic wannabes, and confidantes of the leading man. Like his grandfather, he began as a child performer, billed under his birth name of Keith Mitchell. By age seven, he had a recurring role on the ABC family series "Eight Is Enough" as a playmate for Adam Rich's Nicholas. The following year, Coogan got his first real chance to shine in "A Question of Love" (NBC, 1978), in which he was the son of a lesbian (Gena Rowlands) and the object of a custody battle between his parents. He then landed the role of the youngest of a group of orphans who became "The MacKenzies of Paradise Cove" on that short-lived 1979 ABC series before joining the cast of CBS' "The Waltons" (CBS) for its last season in 1979-80. After a recurring role as Susan Sullivan's son on the ABC sitcom "It's a Living" (1980-81), he again played an orphan in the CBS TV-movie "Tales of the Apple Dumpling Gang" (1982) and for four episodes of its short-lived 1983 spin-off "Gun Shy." (Perhaps ironically, he was replaced by former co-star Adam Rich for the remaining two episodes).