In Bible crocodile is mentioned as one of the monsters of chaos. Because of this fact crocodile was later associated with the Devil in Christian symbolism. His natural enemy hydra kills him from inside like Jesus Christ destroyed Hell after having descended there for three days. Hydra represents Christ and crocodile stands for Hell. The hydra rolls itself into damp mud till its look is indistinguishable, and then makes its way into the mouth of the crocodile, which swallows it unawares, and instantly bursts asunder. During the Middle Ages stuffed crocodiles were chained on the walls of the churches. They represented chained Devil.