Guinea pig

Guinea pigs are the small animals Andrew Ketterly used in his experiments with the Magic Rings. Due to his experiments, several guinea pigs were transported from our world to the Wood Between the Worlds using the yellow rings. Digory noted their presence there when he arrived in order to save Polly. The guinea pigs seemed perfectly happy with their new surroundings, and rather than return them to the cruel hands of his uncle, Digory decided to leave them there. With no means of leaving the Wood, it can be safely assumed that they remained there, as the Wood's only known permanent inhabitants. It is not known whether or not there were guinea pigs and their talking counterparts in Narnia.