The title 'The Spider's Gift: A Ukrainian Christmas Story' implies that the spider is the main character. It is the one associated with the gift which is central to the story. However, in a Ukrainian Christmas story, there might be other characters like a poor child or a family that the spider's gift impacts. But still, the spider holds the key role as it is the giver of the gift. It could be a magical spider that uses its special gift - giving ability to bring about some positive change during the Christmas season in the Ukrainian context.
Probably the spider is the main character. But there could also be other characters like the recipients of the spider's gift. For example, if it's a family that the spider helps during Christmas, the family members could also be important characters. However, given the title, the spider is the one that stands out as the main character as the whole story seems to revolve around its gift.
Since it's about the spider's gift, the spider is likely to be one of the main characters.