Once in the Morning (1981)

One morning a small pretty duckling Krya-Krya went for a walk. He was still very stupid, but because he was friends only with his own shadow, he decided that no one needed him anymore. Humming a merry song, the duckling played with a ball, and it seemed to him that the shadow from the wall perfectly discards the ball. The chicken was so eager to play with the duckling too, but he roughly pushed him away. The same fate befell the sweet little goat. And then, having plenty of fun, the duckling ran through the meadow and accidentally fell into a deep dark pit. Oh God. It was so scary and damp, and most importantly, his best friend - a shadow was not going to help him out. It was simply not here.

Unfortunately the movie Once in the Morning is not yet available on HBO Max.