Vintage Christmas cards can be beautiful and festive, or they can be downright incomprehensible. What does an image of a frog murdering another frog have to do with the holiday? Or a dead bird? Why are these cards so weird? If you were to ask the people who bought them, they would say, why not? Stephanie Boydell of Manchester Metropolitan University said that card manufacturers would recycle popular images from non-Christmas projects to keep up with demand.
So why were such odd things depicted?
"They're only odd to our eyes," Ms Boydell says.
"The Victorians had a different idea to what Christmas was about - not particularly Christian, but a time of good humour. You may find a mouse riding a lobster strange - I find it funny. It's horses for courses."
See more of those Christmas cards that make you wonder at BBC News.