Return of the King, The (1980), produced and directed by Arthur Rankin Jr. and Jules Bass.
We return with the same illustrators and voice actors as The Hobbit (1977). As with the books the story is darker and more adult than the The Hobbit.
1hr37m allows only a brief treatment. The beginning is blenderized, set in Rivendell after the events where the Minstrel of Gondor relates the tale of "Nine Fingered Frodo and the Ring of Doom", which is in the book but not in that time or place.
We jump directly to Frodo and Sam trying to get into Mordor. Pippin and Gandalf are in Minas Tirith and Merry in Rohan.
We do not have: Arwen, Legolas, Gimli, Faramir, Shelob or the Army of the Dead. Aragorn is mentioned as the rightful King of Gondor, but does not appear until towards the end.
That's a lot missing.
As in The Hobbit (1977) the illustrators put in details from the text that Peter Jackson could not be bothered with. And again, the music is truly awful, dreadfully inappropriate and distracting.
Pedantic notes:
Contrary to the rush to get through the episodes we do have, Sam's temptation to take the Ring for himself goes on forever. It is straight from the book but we don't have time for it.
The Nazgûl are visible and ride flying horses!
Quite properly, Minas Tirith is surrounded by townlands.
We see Denethor enfeebled, which is not correct.
Properly he has a Palantír, something Jackson omits. It is how Denethor's mind was broken by Sauron, an important plot point.
Extensive quotes from the text in this section, more than Jackson uses.
We have the Watcher statues at the gate of the tower of Cirith Ungol and the barrier they project. Jackson shows them but they are not used. Properly a Nazgûl appears as Sam and Frodo escape.
Sam happens to find the Phial of Galadriel. Frodo explains later: "It's a secret". Nothing for the audience.
As in Jackson we see only a red Eye for Sauron, and searchlight eye-beams. Not in the text.
We see this: "Then the Black Captain rose in his stirrups and cried aloud in a dreadful voice, speaking in some forgotten tongue words of power and terror to rend both heart and stone."
Theoden falls and dies without last words. Eowyn and Merry do tag team Angmar, who this time is properly invisible and rides a fell beast.
Aragorn leads the army to the Black Gate but there is no battle, just an earthquake. Eagles save everyone, which is needlessly stupid.
It is hinted at the end that over time Hobbits will grow into Men, which I have never heard before.