Warped settings and odd characters adorn the 1937 cartoon “Porky in Wackyland” but, as is usual in the case of animation, it was all done before.
In the 1930 cartoon “Mars,” Oswald the rabbit ends up on the red planet with a bunch of strange creatures and sparse backdrops with weird plants. One is a pig-kangaroo, another is a dog-rooster. Their presence is the gag.
Both Tex Avery and Pinto Colvig worked on this, so perhaps some of they’re responsible for some of these.