Caravan Of Courage: An Ewok Adventure (1984)
"A movie that took place on the Ewok planet (not Return of the Jedi) where a little girl and her brother crash land and are helped by the Ewoks, and they get caught in a giant spiderweb, and one of them gets sucked under a lake and can't break the surface of the water because it'a like glass."
Rik Mayall was a legend.
I also found out there are deleted scenes, including one were the Horned King's undead army murders his henchmen in a very disturbing and frightful way. The movie's a lot darker than any Disney film I know of.