Jerry is Mr. Spejbl and Harvie's dog. He's an endearing, vivacious black and white fox terrier, a dog with a strong personality who is loved by all the protagonists in the story and is happy to help them at all times.
Harvie is a boy of approximately eleven years, who is in the fourth grade at school. He is very active, something of a mischievous rascal, but at the same time he has a sense of justice, and in his mischief he means no harm. He is capable of talking his way out of a number of unpleasant situations.
Monica is Harvie´s classmate from the fourth grade so she is approximately at the same age. She acts like a nice and decent girl with excellent grades at school. Although she does not agree with Harvie´s rascalities, at the end she almost always lets him break her into a game and experiences with a variety adventures. She is a very good friend, who likes Harvie and never leaves him alone.
Mr. Spejbl is Harvie's father, who is approaching 50 years old. He works as a caretaker in the town puppet museum. He is very fond of his son Harvie, but he sometimes finds it difficult to express this sufficiently comprehensibly. He tries to bring his son up rigorously, but in the subsequent debates that ensue, Harvie usually outsmarts his father.
Granny or Mrs. Katarina is a retired teacher in her sixties. She lives alone with her granddaughter Monica, and it is only thanks to her that Monica is so educated and well brought up.
All together Brainy, Grumpy and Dimwit are inseparable three-puppets, once created by the puppeteer Bastor. They are watchmen of Bastor link and if they succeed in certain conditions, becoming alive. Each of them has a distinct character. Brainy is well-being of all kinds of knowledge. He likes to share his knowledge and sometimes it could border with indoctrination. He is gentleman with a slick and slightly obsolete speech.
All together Brainy, Grumpy and Dimwit are inseparable three-puppets, once created by the puppeteer Bastor. They are watchmen of Bastor link and if they succeed in certain conditions, becoming alive. Each of them has a distinct character. Grumpy is born pessimistic, eternally bruising and always easily annoyed. He will never miss and opportunity to catch someone with sarcastic comment or an ironic announcement.
All together Brainy, Grumpy and Dimwit are inseparable three-puppets, once created by the puppeteer Bastor. They are watchmen of Bastor link and if they succeed in certain conditions, becoming alive. Each of them has a distinct character. Dimwit approaches to everything with enthusiasm that not prevent him from do the things in wrong way. He has heart in the right place and always believes that everything will go well. When he is agitated, he stutters and in matter fact he is agitated almost all the time.
