Lavagnino was born to voice actress Hope Levy and screen writer Tom Lavagnino. At 14 months old, he was on the cover of TIME magazine where he was dressed up as Albert Einstein. He was cast for Bravest Warriors as the role of Catbug, "a creature that’s half-cat, half-ladybug, who’s actually a big draw for the series simply for the random comments he makes and the sound of his voice." The series was broadcast in 2013, and he participated in the Cartoon Hangover panel for Comic-Con 2013 when he was seven years old, as well as an autograph session for Catbug-related comics at Comic-Con 2014.
He provided a voice in the trailer for the 2014 film The Boxtrolls. In 2015, he was cast as the voice of the younger version of Grizzly in We Bare Bears. He also voiced the character 'Mr. Muffin' in the Asdfmovie series created by TomSka. He just recently appeared as the dog "Rolly" in the new Disney Junior show Puppy Dog Pals. This marks his first extremely major role in voice acting, even if it is a show with the target audience being small children and toddlers.