Adler was born in New Jersey in 1956. His family later moved Nanuet, Rockland Country, New York, and later to Massachusetts in the 1960s. As a child, he was a fan of multiple TV series, including The Three Stooges and Rocky and Bullwinkle.
Adler's first career in acting was in 1971 in a commercial. Later, he starred in Torch Song Trilogy in 1984 and 1985. In television, he has landed many roles in numerous shows, including My Little Pony, Jem, The Karate Kid, The Wizard of Oz, TaleSpin, The Emperor's New School, Bubble Guppies, Jungle Cubs, Rocko's Modern Life, Cow and Chicken, Tiny Toon Adventures, and The Tom and Jerry Show, in addition to The Lion Guard and the other The Lion King spin-off show, Timon & Pumbaa. He has also worked in the crew of many shows, such as Rugrats and All Grown Up.