MYT03 Fionn mac Cumhail

In both Irish and Manx popular folklore, Fionn mac Cumhail (known as "Finn McCool" or "Finn MacCooill" respectively) is portrayed as a magical, benevolent giant. The most famous story attached to this version of Fionn tells of how one day, while making a pathway in the sea towards Scotland – The Giant's Causeway – Fionn is told that the giant Benandonner (or, in the Manx version, a buggane) is coming to fight him. Knowing he cannot withstand the colossal Benandonner, Fionn asks his wife Oona to help him. She dresses her husband as a baby, and he hides in a cradle; then she makes a batch of griddle-cakes, hiding griddle-irons in some. When Benandonner arrives, Oona tells him Fionn is out but will be back shortly. As Benandonner waits, he tries to intimidate Oona with his immense power, breaking rocks with his little finger. Oona then offers Benandonner a griddle-cake, but when he bites into the iron he chips his teeth. Oona scolds him for being weak (saying her husband eats such cakes easily), and  feeds  one  without  an iron to the 'baby', who eats it without trouble.                   .
In the Irish version, Benandonner is so awed by the power of the baby's teeth and the size of the baby that, at Oona's prompting, he puts his fingers in Fionn's mouth to feel how sharp his teeth are. Fionn bites Benandonner's little finger, and scared of the prospect of meeting his father considering the baby's size, Benandonner runs back towards Scotland across the Causeway smashing the causeway so Fionn can't follow him.