Mbh 3.145.1f

And filled with the sounds of the shell, and with the shouts of Bhimasena, and also with the reports produced by the striking of his arms, the caves of the mountain seemed as if they were roaring. And hearing those loud arm-strokes, like unto the crashing of thunder, the lions that were slumbering in the caves, uttered mighty howls. And being terrified by the yelling of the lions, the elephants, O Bharata, sent forth tremendous roars, which filled the mountain. And hearing those sounds emitted, and knowing also Bhimasena to be his brother, the ape Hanuman, the chief of monkeys, with the view of doing good to Bhima, obstructed the path leading to heaven. And thinking that he (Bhima) should not pass that way,(Hanuman) lay across the narrow path, beautified by plantain trees, obstructing it for the sake of the safety of Bhima. With the object that Bhima might not come by curse or defeat, by entering into the plantain wood, the ape Hanuman of huge body lay down amidst the plantain trees, being overcome with drowsiness. And he began to yawn, lashing his long tail, raised like unto the pole consecrated to Indra, and sounding like thunder. And on all sides round, the mountains by the mouths of caves emitted those sounds in echo, like a cow lowing. And as it was being shaken by the reports tottering, began to crumble all around. And overcoming that roaring of mad elephants, the sounds of his tail spread over the varied slopes of the mountain.