I've seen this too, the dragon was actually a more serpentine version of the Jabberwocky, a longstanding part of Alice Through the Looking Glass, Lewis Carroll's sequel to Alice in Wonderland.
The film is variously called Alice in Wonderland or Alice Through the Looking Glass, but the important facts is that it was made in 1985 for television audiences. It was so long it was shown in two parts, so it's running time was probably around four hours.
Here's imdb.com's page for Alice
Through the Looking Glass.
Mostly I remember the Jabberwocky scene, the woman thinking everything needed, "lots of pepper!" the chess pieces, and the pudding dessert that Alice kept trying to cut, but would reform (it had to be passed to every person who wanted some, and then it would break into pieces, because, it's a "backwards world").