This movie came out before Lord of the Rings The Two Towers movie. So, calling Gurgi's voice a ripoff of Gollum's is pointless.
"HOPSCOTCH!"
Some people call Gurgi a rippoff?Stupid
Amos Slade,you trigger-happy lunatic!Give me that gun!
Actually, the animated Lord of the Rings movie was released in 1978 (seven years before the Black Cauldron) so it is entirely possible that John Byner took inspiration for Gurgi from Peter Woodthorpe's portrayal of Gollum. Due to the immense number of similarities between the two voices and the characters themselves I'd say it was likely that this was the case.
shareWell since The Book of Three, the first book in the quintet the movie was based upon, was written in 1964 and that the character Gurgi fits the description in the books. I find it rather unlikely that it's a ripoff.
It`s far easier to start a war than to end one.