This sound effect can be found on Sound Effects in Stereo Volume 2, which was made by Audio Fidelity. It's a higher quality version of Elephant Trumpet Growl from Clack! from Pro Sound Effects. However, it’s unknown if this sound was actually recorded from an African elephant. One of these trumpets was later excerpted and released in low quality on the A1 Free Sound Effects library as "elephant2" and on Shareware Breakthrough Soundworks as "ELEPHNT1". It shouldn’t be confused with Roland Elephant Trumpeting Sound, which starts off sounding similar. Links: https://soundeffects.fandom.com/wiki/Audio_Fidelity,_African_Elephants#Audio_Samples