What actors and actresses appeared in Myshonok i koshka - 1983?

You're likely referring to the 1983 Soviet film "The Little Mermaid" ("Rusalka" in Russian). Here are the main actors and actresses:

* Marina Neyolova as Rusalka (The Little Mermaid)

* Vladimir Vysotsky as Prince

* Alla Demidova as The Witch

* Igor Yasulovich as The King

* Olga Mironova as The Queen

* Evgeny Leonov as The Innkeeper (voice role)

* Boris Novikov as The Old Fisherman (voice role)

The film was directed by Aleksandr Ptushko.