Since we don't have the full story, it's hard to say for sure. However, it's likely that the main character is the friendly tree. Then there could be supporting characters like birds that build their nests in the tree. Maybe there's a deer that takes shelter under the tree during a storm. There could also be a gardener or a forest ranger who takes care of the area around the tree and has a special bond with it.
I'm not sure as I haven't read it specifically, but it might be about a tree that has some friendly interactions with other characters, like animals or people.
There could be stories like kids building a secret club in the tree house, having picnics up there, or using it as a hide - out during a game of hide - and - seek.
Well, it could be about many things. Maybe it's about the relationship between a big tree and a small tree in a forest. For example, the big tree could be protecting the small tree from harsh weather or animals. It might also be a story of growth, where the small tree looks up to the big tree and tries to grow as tall and strong.
The moral could be about growth and protection. The big tree might represent the older generation or those with more experience protecting and guiding the little tree, which stands for the younger or less experienced. Just like in life, the elder ones should help the younger to grow in a healthy way.
A Xenomorph might be friendly if it formed a symbiotic relationship. For example, if it realized that by working with other species, it could get more food or better living conditions. Say there was a planet where the Xenomorphs and another species both needed a certain resource. Through cooperation, they could both thrive, and the Xenomorphs could become friendly towards the other species over time.
Maybe it was the eldest child. In many families, the eldest is given the honor of placing the angel on top of the tree as a sign of their growing responsibility and to mark their special place in the family during the holidays.