These festive fellas are a type of marine worm that resides on coral reefs all over the world. That being said, they are most common in the Indo-Pacific ocean as well as in the Caribbean.
These little worms are called so because of their appearance. They literally look like tiny little Christmas trees, in all different colors. However, their true names are Spirobranchus giganteus.
Their bodies are tube shaped and they have appendages on them that act as their breathing system as well as catching their snacks.
They are very small, measuring only around 1.5 inches in length.