O, ’twas a din to fright a monster’s ear,
To make an earthquake! sure, it was the roar
Of a whole herd of lions.
– William Shakespeare
The Tempest, Act 2, Scene 1. Would-be assassin Antonio, responds to Alonso asking why he and Sebastian had their swords drawn. He lies and says that they heard a noise like "a whole herd of lions" that would frighten a monster. It’s more like Antonio is the monster, having persuaded Sebastian to join a conspiracy to murder Sebastian’s brother and king Alonso.