(written from a Production point of view)
The diminutive (5 feet [1.5 m] tall) and cherubic Williams is also an actor, appearing in films and many television guest appearances, notably as the role of the Devil's representative, "Swan" in the cult film Phantom of the Paradise, a rock and roll remake of Phantom of the Opera, along with his role as Little Enos Burdette in the Smokey & The Bandit film series, and as Virgil, the genius orangutan in Battle for the Planet of the Apes. Williams worked closely with Jim Henson's Henson Productions on The Muppet Movie, most specifically on the soundtrack. Williams collaborated with frequent Star Trek composer Jerry Goldsmith for the song "Flying Dreams", the ending theme from the Don Bluth film The Secret of NIMH, which featured a young Wil Wheaton.
He is also well known for providing the voice of The Penguin in Batman: The Animated Series; two of Penguin's principal henchmen, Eagleton and Sheldrake, were voiced by John de Lancie and Barry Gordon, respectively. The show also featured recurring appearances by Adrienne Barbeau and Loren Lester. Other Trek performers who appeared in the same episodes as Williams included Ray Buktenica, Lindsay Crouse, Diana Muldaur, Lori Petty, and Paul Winfield.