These are Skywalker Sound sound effects. They were most likely created by Christopher Boyes, and debuted in Dinosaur (2000). The first moan is one of the takes of Jurassic Park, T-Rex - Exclamation Roar in a -24 pitch. Links: https://soundeffects.fandom.com/wiki/SKYWALKER,_CREATURE_-_LOW,_HEAVY_MOAN#Audio_Samples