Vikings assumed Chichillen was an ice sculpture at the Snoggletog feast, but its actually a clever ruse by Tuffnut to let his favorite pet eat food straight off the table.
— Dragons: Rise of Berk
Chichillen looks like an ordinary chicken in shape. However, it holds the appearance of an ice sculpture, because Tuffnut disguised her by unknown means. Chichillen may be a hen, as she has the same conformation of hens in the Franchise. Her feathers, when disguised, are a pale icy blue, and Tuffnut seems to have made small icicles form upon her feathers in some places, as a result of his ice sculpture disguising.