Hatchling to Adult
The Fathomfin has an expandable, pelican-like throat. When expanded, its skin becomes translucent, allowing its rider to see through it and observe their surroundings, similar to a glass bottom boat.
Behavior and Personality
Not much is known about the Fathomfin's personality or behavior, but they are generally peaceful dragons.
When the Dragon Riders are about to reach Nepenthe, Hiccup uses his spyglass to observe a Fathomfin surfacing in the distance before commenting on its mysterious presence. Fishlegs immediately got excited about it and wants to know more about the new dragon, but Hiccup tells him that investigating the situation on Nepenthe is currently more important than studying the Fathomfin.
- The Fathomfin's name was first revealed in a commentary regarding the graphic novel project The Fire Tides.
- ↑ Headlines and Dragonvines: A Conversation with Richard Hamilton. (Date Posted - October 2, 2018). Dragon Academy Dropouts on Tumblr.
- ↑ "It also has some big moments for Astrid, a Viking Atlantis, the Fathomfin dragon 1st teased in #TheSerpentsHeir — oh, and a shirtless Hiccup." (Date Posted - September 15, 2018). Twitter.