How bad is it? It's in the bottom 3 all-time worst Xmas films for kids.
Should you see it? Yes - it's entertainingly bad.
A boy saves a cat from a tree and falls, perhaps being knocked unconscious, but certainly being knocked from black and white to color film with poor post-synched sound. His reward from the cat's owner, who is now a witch, is a ring with a seed in it that, when planted, will grow into a tree by Christmas (it's currently Halloween) that will grant three wishes to whoever wears the ring. His first wish is power, which he uses to move fire trucks and force a pie fight. His next is to have Santa to himself, which turns out to be a terrible mistake, involving the National Guard. There's a scene with a giant woodsman in fur that's extremely creepy - unintentionally. There's a scene of the boy's dad starting a lawnmower with "comic" sound effects that takes FOREVER and a race with a turtle. The boy's third wish is to undo his others and he learns a valuable sappy lesson. With an appearance by Terry Bradshaw (alas, not the bald quarterback).