From the Super Mario Wiki
Michelle Hippe is an American actress and voice actress who portrays Larry Koopa in Mario Kart 8, replacing Lani Minella who portrayed Larry in previous games. Michelle reprises her role in Mario & Luigi: Paper Jam, Mario & Luigi: Superstar Saga + Bowser's Minions and Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, and her Mario Kart 8 voice clips for Larry are recycled in its Nintendo Switch remake. Michelle Hippe also voiced Larry Koopa in Mario & Sonic at the Rio 2016 Olympic Games. Michelle Hippe provides Larry with a higher-pitched voice compared to Lani Minella's portrayal of him.