Yoyo™
A little rascal and a livewire, cheeky and full of witty thoughts and cunning plans. He whisks through the stories like a whirlwind and is always good for a surprise, either with his crazy ideas or his cocky comments about his companion, Doc Croc. Quick-witted and clever as he is, he always has an answer ready.

Doc Croc™
He is a real bookworm and the "scholar" of the pair: well-read, educated, rather reserved and a little unworldly. The practical things in life are not his cup of tea, so he is the precise opposite of Yoyo. Sometimes he can be really pedantic, but in all the adventures he is always faithful to his friend.

The fairy-tale book
It holds all the treasures of the Grimm brothers' fairy-tale treasure trove and "gives wings" to the imagination, in the true sense of the word: at the beginning of each episode, it comes flying through the air and opens up new pages full of adventures. Yoyo and Doc Croc sit on the fairy-tale book; on its cover it shows the faces of the Grimm brothers, which come magically to life.