Final answer:
The model narrative and informational text both highlight the peuchen's ability to shape-shift, a defining characteristic of this mythical creature.
Step-by-step explanation:
The similarity between the peuchen in the model narrative and the description of the peuchen in the informational text is that they both mention the peuchen's ability to shape-shift. This characteristic of the mythical creature is often highlighted both in fictional narratives and in the folklore or cultural discussions about mythological entities. While both texts could also describe the creature's appearance, habitat, behavior, and historical context, the shape-shifting ability is a unique and defining attribute that stands out in both types of texts.