Leopold the Cat

"Let's live in friendship, guys."

—Leopold

Leopold the Cat (Russian: Кот Леопольд, Kot Leopold) is a Soviet/Russian animation series about the pacifistic, and intelligent cat, Leopold. Leopold always wears a bow tie even when swimming. He is always confronted by two mischievous mice, Grey and White (Mitya and Motya). It was filmed by T/O Ekran in 1975 - 1987 and its runtime is 87 min (10 series). As of 1987, there were 11 episodes in total. Eventually, in 1995, most of the episodes were released on DVD.

Pretty much a Soviet version of Tom and Jerry, especially in the later versions which tacked on an aesop catchphrase at the end of each episode.

Tropes used in Leopold the Cat include:

Amusing Injuries: Averted for the most part, but played straight during the sillier parts of an episode when Toon Physics take over.
Animation Bump: The first series looks eerily like South Park, and may come off as downright creepy. Fast-forward to the third series and it's tons more easier on the eyes.
Actual Pacifist: In the third series. You can prank Leopold all you want, the most he'll do is turn the prank around back on you, with brilliantly hilarious results.
Cats Are Mean: Gloriously averted starting with the third series. Leopold positively gives Danny a run for his money.
Funny Animal
Early Installment Weirdness: May be the case with the first series, as it looks depressing from what evidence can be gleamed from YouTube today. Just LOOK at poor Leopold!
Laser-Guided Karma: Every single time with the two mice. They try their damndest to have fun at Leopold's expense, only for their pranks to continually backfire at them.
Mood Whiplash: In the absence of subtitles, non-Russian speakers can only assume this with the episode where Leopold gets "miracle tablets" from a random physican appearing out of nowhere seemingly by magic. The rest is Leopold going on a musical rampage tormenting the mice for what they did to him just minutes ago.
Once an Episode: The mice will inevitably apologize to Leopold at the end of an episode, to which Leopold responds with his catchphrase.
Squashed Flat: The mice, again.
Talking to Himself: Gennady Khazanov voiced all roles in the first series, Andrei Mironov voiced all roles in the second series and Alexander Kalyagin voiced all roles in the series from third to tenth.
The Voiceless: Averted in the first series. In the more recent series, dialogue is very minimal, limited majorly to the catchphrase, whispering between the mice and conversation from random characters appearing at the time.