Sea Slug (Franchise)

Sea Slugs do not pictorially appear in the How to Train Your Dragon Franchise, but are mentioned on several occasions.

Description
The term "Sea Slug" is actually a general term to describe anything that looks slug-like with on observable shell and lives in the sea. This can include any number of invertebrate groups world-wide, including but not limited to: Nubibranchs, Sacoglossa, or Sea Cucumbers (Class Holothuroidea). Other than "slug-like" and "shell-less", Sea Slugs come on a vast variety of forms and colors, and diets vary tremendously as well.

Function
In the How to Train Your Dragon Franchise, Sea slugs are only mentioned a food for dragons, especially the Razorwhip.

In actuality, some creatures that fall under the blanket term "Sea Slug" are also edible to humans. Sea Cucumbers are highly prized in Asian cuisine. They are also used in traditional medicine to treat anything from cancer to arthritic pain, but so far no scientific studies back these claims.

Appearances
Mentioned in "Stryke Out"

Mentioned in that RTTE episode where they find Razorwhips like sea slugs and track down Heather