Czechoslovakian animation was indeed famous abroad even though communist regime regulate everything they could. Good to mention:

- Krtek (Little mole) by Z. Miler - its never dying cartoon that basically every kids since 1y still watching in Czechia https://www.youtube.com/channel/UC8ZKvF049Iku9y41WpIUUCA

- animated feature films by Karel Zeman (I was a student at school that is located in ateliers where he was making his films) https://youtu.be/fP7T9J6AiHM

- Broučci by J. Trnka https://youtu.be/8Apo0tj5Rso

- Bob a Bobek (one of director was my teacher at high school) https://youtube.com/playlist?list=PLAqhvvA2ar-wN0PRnQVxaEsre...

- Pat a Mat (one of animator was my teacher as well) https://youtube.com/playlist?list=PLAqhvvA2ar-w9QewRWADbr6DW...

- surrealist animation films by J. Švankmajer https://youtu.be/tK_l74cSPGY

- many more