Talking animal
Appearance
The talking animal is a common theme in folk tales and literature. The "Three Little Pigs", "Little Red Ridinghood", and the "Musicians of Bremen" are examples of fairy tales featuring talking animals.
In an ancient example, the animals surrounding Jesus in the manger were said to have talked. In modern literature, The Chronicles of Narnia by C. S. Lewis featured both talking and non-talking animals.
Having the animals talk enables storytellers to combine the basic character of the animal -- the supposed rapacity of the wolf -- with human behavior -- attempting to trick the pigs. The animals can also interact with humans better if they talk.