Křeček v noční košili (Hamster in a Nightshirt) is a six-part television series for children, which was co-produced by Czechoslovakia and West Germany in 1987 by director Václav Vorlíček.

The main character is young Kája Berka, who visits his grandparents in the town of Ružbach.

There he sleeps in a borrowed nightgown from his great-grandfather - and thanks to it, he is transported in his dream to the time when his great-grandfather taught at the local school and shocked the neighborhood with his ingenious inventions.

However, in an attempt to transfer his inventions to modern times, engineer Křeček appropriates these inventions (among other things because he was competing with Kája's father for the position of chief designer of the automobile company).

The Kreček family basks in the media's favor, while the Berks are embarrassed - so Kája and his friend Aleš Chvojka, using another of his great-grandfather's inventions, get into the thief's head and begin to influence and control him in an attempt to seek justice.