I also have a sneaking suspicion they might have borrowed elements from the book The Black Cauldron, along with the other books from the Chronicles of Prydain, but that might be a little far fetched...
"I've been living on toxic waste for years, and I'm fine. Just ask my other heads!"
Though this film is not all that faithful to the Chronicles of Prydain, but then it combines elements of the first two books so would have been a big ask...
There's no doubting the similarities between the two books, but they are really just surface similarities (boy on quest, minions, a sacred item, evil horned king), so there would most definitely be those similarities in both movies.
Dunno if they took things from Black Cauldron the movie though...
Given the fact that this film was not very popular, I don't think Peter Jackson or Andy Serkis or anyone else looked to it as a source of inspiration. But, as I've said before, there's a maquette of the main villain from Legend in Jackson's room and that film's not all that popular nowadays.
And yet is also a seriously awesome film in its own right. For some reason, Fantasy usually doesn't draw the kind of big numbers in the box office as other genres. Lord of the Rings was a bit(large bit, mind) of a fluke. Willow, likewise, was unusual for a fantasy film in its popularity. The most popular fantasy film of the 80's that I'm aware of, Willow, didn't even manage to garner double its production cost in revenue.
Beyond that, Black Cauldron was an incredibly dark film for Disney at the time, and a lot of parents just weren't willing to take their kids to see something so scary.
It is loosely based on the Chronicles of Prydain, which in turn were based on the Mabinogion which is why some of the names are a little different than the norm, such as Fflewddur Fflam, the Mabinogion is Welsh. Welsh prose, no less. Which is why the pronounciation of such names as Fflewddur Fflam annoy me, as I am Welsh. The way she says 'Eilonwy' goes through me and she sounds like she's struggling to say it every time.
Sorry, tangent, but does Disney have a Welsh department which supplied them with these names? Of course they don't, they would have pronounced them right.
I confess that I haven't read the Welsh epic, but watching the Black Cauldron, to me it seemed like an absolutely shameless LOTR rip-off. I practically think that the Tolkien estate could sue this author for copyright infringement.
Just look at the comparisons:
Village = shire Cottage = Bag End Old Man at cottage & old bard = Gandalf composite Young boy on quest + pig = Frodo composite Dog-like creature = Gollum Cauldron = The One Ring Pig's mirror of water = Galadriel's mirror of water Horned King = Sauron Horned King's castle = Barad Dur Horned King's land = Mordor Army of dead = army of dead (same element) Winged pterodactyls = Ringwraith flying creatures Dog-like creature falls in cauldon = Gollum falls into lava Castle implodes = Barad-dur implodes
I'm not saying that the Black Cauldron is a bad film (it's hit and miss), but it's much more obviously a Tolkien rip-off now that the LOTR films have cemented Tolkien in public consciuosness.