Another father, called Abba Helle...

…had persevered since childhood in the ascetic life. He often carried fire to his neighboring brethren in the fold of his tunic, and stimulated them to advance to the point of performing miracles, saying to them, “If you practice true ascesis, then you will show the supernatural signs of virtue.” 

Once on a Sunday he went to see some monks and said to them, “Why have you not celebrated the Divine Liturgy today?” When they replied that it was because the priest had not come from the other side of the river, he said to them, “I shall go and call him.” But they said it was impossible for anyone to cross the ford, partly because of the depth, but most of all because there was a huge beast at that spot, a crocodile which had devoured many people. The father did not hesitate. At once he jumped up and rushed into the ford. And immediately the beast took him onto its back and set him down on the other side. On finding the priest at his place, he entreated him not to neglect the community of brothers. The priest, seeing that he was dressed in a rag with many patches, asked him where he had found it, saying, “You have a most beautiful mantle for your soul, brother,” for he was amazed at his humility and poverty.

He followed Helle back to the river. As they failed to find a ferry, Helle let out a cry calling the crocodile to him. The animal obeyed him instantly and offered its back as a raft. Helle asked the priest to climb on with him. But the priest was terrified at the sight of the beast and backed away. While he and the brothers who lived on the other bank watched, seized with dread, he crossed the ford with the beast, came ashore, and hauling the beast out of the water, said to it, “It is better for you to die and make restitution for all the lives you have taken.” Whereupon the animal at once sank onto its belly and died. 

Historia Monachorum in Aegypto 12.1,6-9