Frank has provided the voice for 8 of the original 14 Decepticons in the The Transformers cartoon: Megatron, Soundwave, Skywarp, Lazerbeak, Rumble, Frenzy, Ravage, and Buzzsaw. He voiced two of the original Autobots as well: Trailbreaker and Mirage, as well as one of the Dinobots (Sludge) that also appeared in the first season.
He has done every voicing of Freddy "Fred" Jones for the Scooby-Doo series with the sole exception of A Pup Named Scooby-Doo. Even in parodies and cameos on different TV shows, he has always done his voice.
In Steven Spielberg Presents... Tiny Toon Adventures, he voiced Furrball, Gogo Dodo, Calamity Coyote, Little Beeper, Byron Basset, Uncle Stinky Pig, Henry Bear and Ralph the Guard, who later appeared in Animaniacs, where Frank not only voiced Ralph, but also voiced Thaddeus Plotz, Buttons, Runt, Flavio Hippo and Chicken Boo.