Nu, Pogodi!

its kinda like Soviet tom and jerry with a wolf and rabbit

I remember someone from a post-soviet country showing me Hedgehog in the Fog and being like "That's what a Soviet childhood looked like! We only had depressive entertainment! Traumatic!" (they were born many years after the USSR collapsed lol) I personally think it's interesting, albeit dark in some places, though the artistic medium is definitely worth a shot, as it had many interesting effects such as the segment with the tree.

Gena the Crocodile

An extremely wholesome and heartwarming series about an anthropomorphic alligator who works at the zoo and wants nothing more then to make some friends. The humor is very well done.

The songs are also beyond catchy.

https://youtu.be/q_-OR5HmGso

Secret of The Third Planet is one of my favorites! Very strange with fantastic animation and visuals!

Interplanetary Revolution The grandaddy of Soviet animation from 1924.

Hedgehog in the Fog I've always found this one oddly beautiful.

The Millionaire Kind of includes a dog, from 1963.

This movie is excellent, we watched it recently on one of the Hexbear movie nights. There's also some live action scenes mixed in that are hilarious, no animal characters though.

https://youtu.be/LDpMad20EvI

AMBA is a pretty good sci fi cartoon https://en.wikipedia.org/wiki/AMBA_(animated_film)

Umka is a pretty popular one. I think every Russian kid has watched it at some point.

Винни Пух is the Eastern European Winnie the Pooh, I forget which country produced it, but when my grandma first got internet, she would show me old episodes of it, cool art style, I think it’s from the late 50s or 60s, I highly recommend it

A number of good ones is already mentioned, but one is oddly missing: https://en.wikipedia.org/wiki/Three_from_Prostokvashino There are 3 soviet movies, and one post-Soviet. Ignore the latter. Obligatory animal characters included.

Russian Winnie the Pooh is pretty great.

That Dr. Livesey meme comes from a Soviet adaptation of treasure island, the whole thing is bonkers, it's great.

Polygon is cool.

Technically a full-length animated film, but Бременские музыканты (Bremen Town Musicians) is good.

Kuzya the little domovoy. I sadly don't know if it has subtitles (in case of a language barrier). It has multiple animal characters and even a couple sentient trees

Having thought about it, here's a whole series. The Merry Carousel!

My favourite is about the lonely little Hippo

Ah im gonna have to think real hard to even have a chance of remembering, but one of my exes loved this old Soviet cartoon about a mouse that goes to New York and is surrounded by giant rats and bad people. It was great, I’ll see what I can dig up.

Bolek and lolek - Polish

Pat and Mat - czechoslovakian

Professor Balthazar - Yugoslavian