Lola was my Christmas present from my aunt, but I knew getting her. I had been planning on getting a dog anyway so when I heard that her dog was having puppies, I requested one of them for Christmas. She also came with some toys and little food dishes.
I've received a few pets as gifts, but they were always planned for. I knew about the pets and chose the pets myself. They way in which they were gifts, is either another person payed for them or helped me go get them.
In situations like this, I feel that a pet as a Christmas present is okay. Surprising someone with a pet as a Christmas present is a whole different story though. A person needs to be prepared for a pet, they should never be thrown into that situation.