The Owl is the subject of many children's Nursery Rhymes.
It was once seen as a mysterious and sinister bird only hunting at night when of course evil spirits and witches were known to be abroad!
The owl has been associated with wisdom, witchcraft, weather and death in the various legends and myths of different cultures.
The owl was associated with witches along with other animals such as the Cat, Frog, Pig, Raven, Goat, Wolf, Bat and Mouse, many of these animals are featured in Nursery Rhymes!
These animals were believed to be the witches 'Familiar' - an evil spirit, in animal form, who was used by the witch to perform evil deeds and cast malevolent spells.
The words in 'There was an Owl lived in an Oak' contain rhyming words like "Whiskey, whaskey, weedle" and "Fiddle, faddle, feedle" which children would associate with casting a spell! Click the following link more information about Witches and their Familiars in the Identity and Nursery Rhymes of Mother Goose.