Mitten

A Soviet puppet Stop Motion short made in 1967. Lonely girl wants to have a dog, but her mom wouldn't allow a pet in the flat, so girl imagines that her mitten is a puppy and starts to playing with it.

Can be watched on youtube (no translation needed).

Tropes used in Mitten include:

Disappeared Dad
Not-So-Imaginary Friend
Tear Jerker
No Celebrities Were Harmed: Serious looking dog with a mighty eyebrows decorated with multiple awards is an obvious parody of Leonid Brezhnev, Soviet leader of that time.