The earliest Looney Tunes & Merrie Melodies are said to be Disney copies.
This has much to do with the fact that the creators of the initial LT/MM cartoons were Disney expats (Harmon, Ising, Freleng, etc).
Here is a brief comparison of Oswald the Lucky Rabbit's Trolley Troubles (1927) and Merrie Melodies Smile, Darn Ya, Smile! (1931). Friz Freleng is a credited animator on both films.
It took the injection of new (non-Disney) blood, for the "Warner Bros. style" to eventually emerge a few years later.
![](https://s2.save4k.ru/pic/6_4bFCaTWtQ/maxresdefault.jpg)