Peter could be a character with a special ability related to the dogs. For example, he might be able to communicate with them in a unique way. He sneaks them into the tower because he believes that together, they can achieve something great, like finding a hidden treasure or rescuing someone trapped in the tower.
Maybe Peter is an outcast in his community. The dogs are his only true friends. The tower represents a place of hope or a new beginning for him. He sneaks the dogs in because he wants to start a new life away from the judgment of others, and he thinks the tower can provide that. He may be relying on the loyalty and skills of the dogs to help him build a new home or find a way to survive inside the tower.
Peter could be just an ordinary person with an extraordinary love for dogs. He might be a local boy who has always been fascinated by the tower and decides to bring his furry friends along on his adventure.