Fantasy Animation from the 80's. Companion pulled into ceiling by tentacles. Other turns around and companion is just 'gone' [duplicate]

Question

I have only a few vague memories of this animation, but would like help identifying it:

• From 80's or earlier (watched when I was a child during late 80's or early 90's
• A person (human?) in the animation is travelling with a companion - the companion may be an animal with more than 4 legs (sapient?)? Said companion is lagging behind slightly and gets taken into ceiling by tentacles / taken into trees by vines? When person looks back, the companion is nowhere to be seen and they have to travel on, with no idea where they went. Sad.
• It is likely pure fantasy, as I seem to recall there being strange landscape, flora and fauna but no technology (may be wrong)
• There is death / violence (implicit, possibly explicit) and it was the first animation I saw of this nature, and I remember being shocked and saddened by the above mentioned scene.

That is all I have about the animation but it tugs on my nostalgia gene for some reason. I can say:

• It's not Ghibli
• It's likely not roto-scoped

Answer 1

It's not a perfect match (he does see it happen) but otherwise everything matches a scene from the 1982 Franco-Hungarian animated film Les Maîtres du temps - I saw an English dub on UK TV in the mid-1980s called The Masters of Time. I remember the scene clearly and it features in the plot summary on the Wikipedia page:

traveling with his native companion, Piel has lost his transceiver (and his companion) inside a cave filled with predatory hanging tentacles.

The scene in question is actually available on YouTube: