Freddy the Pied Piper by Walter R. Brooks
Freddy's friends knew that they could always rely on him to help them out of a jam, and when Mr. Boomschmidt and his traveling circus run into trouble, Jerry the rhinoceros turns to upstanding Freddy for some practical advice. In an instant the ever resourceful Freddy swings into action, and quick as you know, plans are made, funds raised, and scattered circus animals found. Freddy does it again, in one of his most memorable and enjoyable adventures.