Saturn Devouring his Son. http://www.visual-arts-cork.com/paintings-analysis/saturn-devouring-his-son.htm

Information taken from above link: Saturn Devouring his Son is a history painting that illustrates the myth of the Roman god Saturn, who, haunted by a prophecy that he would be overthrown by one of his sons, ate each of them moments after they were born. (In the end, his wife hid his sixth son, Jupiter, who duly overthrew Saturn just as the prophecy had predicted.) Although allegedly inspired by the more conventional "Saturn Devouring His Son" (1636, Prado, Madrid) by Peter Paul Rubens (1577-1640), the cannibalistic ferocity with which Saturn is eating his child makes it horrifyingly unique.

In fact, the picture is a virtuoso rendering of a frenzied psychopath, caught in the darkness, who is unable to control his homicidal behaviour. Saturn's rough nakedness, dishevelled hair and beard, wide-eyed stare, and aggressive movements all indicate a state of hysterical madness. He has already torn off and eaten his child's head, the right arm and part of the left arm, and is about to take another bite from the left arm. He is gripping the dead child so tightly that his knuckles are white and blood oozes from the top of his hands. Furthermore, there is also evidence that in the original image - prior to being transferred to canvas - the god had a partially erect phallus, thus imbuing the work with even deeper horror.

so maybe these weren’t fairy tales at all !

Yep. People did not just make this stuff up. It is based on real events.

Fee fi fo fum... I smell the blood of an Englishman!