The answer? Dart from Stranger Things. Dart, the infant monster adopted by Dustin in the show is just one of the handful of sounds explored in a Hollywood Reporter piece on the work of sound editors in popular TV shows.
Initially, Dart’s sounds were simply modified versions of sound designer Craig Henighan making various gurgles, grunts, and roars, but as the monster got older that changed.  As Dart got older, his sounds were a mashup of the Demogorgon from season one of the series and howler monkeys. “Dart is a cousin of the Demogorgon, so it needed to sound [like] the same language,” Henighan told the Hollywood Reporter.
Henighan also shared what he used to make the Shadow Monster sounds. Turns out the Shadow Monster is a mix of bugs and a tornado.
