At a meetup group several months ago, someone gave my son a piece of this plant. Over the summer the leaves off the main part have grown from the sides of the original piece. We aren't sure what this is or how to care for it. It looks related to a Christmas Cactus to me, but the leaves are much larger. Does it grow upright or eventually hang down like a Christmas Cactus? If you know about this mystery plant, we'd very much appreciate any info in the comments!