louder than elephant

There came an answering roar, low but thunderous. It rolled across the savanna and reached them, touching their skins with a threatening sound.
“Listen, Tarzan,” squeaked Nkima. “Kree-gor pand—thunder roar!”
Tarzan nodded. The roar did rival thunder. If this were the gorilla-beast, he was miles and miles away, the jungle lord knew. But the intimidating volume of his roaring carried further than the roar of the lion, or the trumpeting of an elephant.
Beside him, Jad-bal-ja issued a growl that turned into a lifting roar, but that feral defy was not answered.
Against the deep-throated roar of the great terror gorilla, the challenge of the golden lion was akin to that of a cheetah cub against a full-grown panther.


King Kong vs Tarzan, Chapter 61