There is no danger in giving a puppy peanut butter, providing that it is organic with no artificial additives.
However, as puppies are still developing both physically and mentally, feeding something like peanut butter to a youngster may not be the best food choice.
Puppies grow quickly and need the best nutrition that you can provide them with and you should always feed a growing puppy a high quality puppy food.
For some suggestions on the best types of puppy foods you can visit our puppy food article here.