it's been a legend for a long time. Wikipedia: Earliest reports

The earliest report is taken from the Life of St. Columba by Adamnan, recorded in the 6th century. It describes how in 565 Columba saved the life of a Pict, who was being supposedly attacked by the monster. Adamnan describes the event as follows:

"...(He) raised his holy hand, while all the rest, brethren as well as strangers, were stupefied with terror, and, invoking the name of God, formed the saving sign of the cross in the air, and commanded the ferocious monster, saying, "Thou shalt go no further, nor touch the man; go back with all speed." Then at the voice of the saint, the monster was terrified, and fled more quickly than if it had been pulled back with ropes, though it had just got so near to Lugne, as he swam, that there was not more than the length of a spear-staff between the man and the beast. Then the brethren seeing that the monster had gone back, and that their comrade Lugne returned to them in the boat safe and sound, were struck with admiration, and gave glory to God in the blessed man. And even the barbarous heathens, who were present, were forced by the greatness of this miracle, which they themselves had seen, to magnify the God of the Christians".[1]...

Pauper, that was the surgeons photograph and people are still unsure of certianty as in legit or nt, some say yes, others say boat, others say elephants.

Should she be proven existence or left be though?