Perhaps the stray cat finally finds a small corner to hide in as it gets weaker and weaker from lack of food and illness. It curls up and closes its eyes for the last time, with no one to mourn its passing or even know it had ever existed.
Maybe the cat, despite all the sadness, manages to form a little community with other stray animals for support and survival. Or it could be that an animal rescue organization steps in and takes the cat in, nurses it back to health if it was ill, and then finds it a forever home.
Once there was a little stray cat. It was all alone in a cold alley. Its fur was matted and it looked so thin. It meowed pitifully, but no one seemed to care. One day, it got hit by a car while trying to cross the street to find some food. It lay there, in pain and all alone, until it finally took its last breath.
One possible ending could be that the grandpa's family finally realizes how much they've neglected him. They start visiting him regularly, and he slowly starts to regain his old happy self.
The wolf could sacrifice itself to save another animal or even a human who once tried to harm it. This selfless act would be a very sad but also heroic ending to the story.
One possible ending could be that the fruitcake was thrown away in despair, ending up in the trash.
Perhaps the sad caterpillar's situation gets worse. It fails to find enough food or is finally caught by a predator. This would be a tragic ending for the poor caterpillar. However, its story could also serve as a lesson about the harshness of nature for other small creatures.
The ending could be that the doge's owner comes back and realizes how much the doge has missed them. So, they decide to never leave the doge alone for such a long time again and give it lots of love and attention.
Perhaps the brother and sister get separated due to some misunderstanding. Years pass and they both try to move on but deep down they are always sad. In the end, they find out about the misunderstanding too late when one of them is on their deathbed, and they can't make up for the lost time.
One possible reason could be the loss of a loved one, like in the case where the cat's owner died. Another might be separation from friends or family, as the cat that lost its mouse friend. Or neglect, such as when the family focused on the new baby instead of the cat.
One possible ending could be that they never get to see each other again. Jack fades away into his own world and Elsa is left in her ice - filled kingdom, both with a sense of longing and loss.