Just searching on Youtube I found many of the original Dr. Seuss Specials. From my vast VCR collection, I know that there are at least 10 or so more movies including Thidwick the Big Hearted Moose. Here a few of the videos I found as I stepped just a little bit deeper into the rabbit hole. When I get home for break it looks like I am going to have to break out the VHR and VHS tapes because I need to re-establish my Dr. Seuss knowledge. I might reread the books I have at home.
Dr. Seuss On The Loose
When you search for Dr. Seuss TV specials on Youtube this is one of the first results.
The Lorax
The Lorax also appears.
The Cat in the Hat
Then, there is The Cat in the Hat, past these three finding some of the other specials takes a little more elbow grease.
Since these specials aired or the movies were released there have been so many adaptations. Currently, there is a Dr. Seuss land in Universal's Theme Park, and newly animated adaptations continue to be added to the collection. This possibly could be considered an expansion of the Seussian Multiverse I have begun to imagine. The live action films would also be included but to be honest, they are not my favorite adaptations, therefore, I tend to leave them out of what I feel is more of a headcanon at this point.
The newer TV adaptations on the other hand such as The Cat in the Hat's TV show would be considered in my theory however due to the fact they are still animated and follow the general Seussian form. The live action films just do not have the same structure and at times diverge from the known backstory of the original source texts and the original film adaptations. The reanimated versions also diverge from the source texts as well but it is normally in a way which allows for the medium to illustrate more exaggerated elements of the storylines. Thinking about it now, they still maintain the musical aspect of Dr. Seuss films however they normally get rid of the rhyme scheme for the most part unless it is a specific reference to the original source material or works perfectly at the moment.