Insana's highly-distinguishable voice has been featured in many animated television series, most notably Disney's Darkwing Duck as Dr. Reginald Bushroot and Bobby's World as Bobby's Uncle Ted. More recently, he has voiced Pig in Nickelodeon's animated film Barnyard and its subsequent spin-off TV series.
In the 1980s, Insana wrote two episodes for Police Squad! and an episode of Sledge Hammer!; he also served as story editor on both series. Insana then wrote, produced, and acted in the independent comedy films Wedding Band and Masters of Menace.
Insana has also made brief acting appearances in such films as Neighbors, ¡Three Amigos!, Who's Harry Crumb?, Oscar, and Beverly Hills Cop III. He has also made guest appearances on situation comedy series such as Night Court and Mad About You.
In 2008 Insana voiced the role of Barf on Spaceballs: The Animated Series (possibly due to Insana's voice being very similar to the late John Candy). He has also done voice work in the TV seriesGoof Troop, Camp Candy, The Little Mermaid, Pepper Ann, House of Mouse, What-a-Mess, Bonkers, Aladdin, Jungle Cubs, Problem Child, Buzz Lightyear of Star Command, Teacher's Pet and the feature film Tom and Jerry: The Movie.