This sound effect can be found on the Lucasfilm Sound Effects Library, which was made by Sound Ideas. An identical variant can be found on Animal Trax as Hollywoodedge, Rhinoceros Snorts Ea AT048401 as well as a compressed variant on the Wild World of Animals Sound Effects Library as ANIMAL, RHINOCEROS - EATING, LIGHT GROANS, MUNCHING, CALLS. Links: https://soundeffects.fandom.com/wiki/Sound_Ideas,_RHINOCEROS_-_C.U._GROANING_%26_CHEWING,_ANIMAL#Audio_Samples