The Octofin is a gigantic Tidal Class dragon species that appeared in Dragons: The Nine Realms.
It is a fierce dragon that was often hunted by the Shellfire. It lived on the seas and all those who come across it. The creature is introduced in "Into the Deep" when Buzzsaw and his crew captured one that the Dragon Club has helped rescue from a Shellfire.
The Octofin's design is similar to the Brickleback monster from the 2022 Netflix film The Sea Beast, both portraying a crocodile-like body and possessing tentacles.
The Octofin is one of the few dragons with no wings, just like the Woodchipper, Vine Tail, Glass Caster, and Cavern Crasher.
Weapons: Inferno, Astrid Hofferson's Axe, Hiccup's Viking Helmet, Hiccup's Shield, The Mangler (Hiccup's Bola Catapult), Dragon Root Arrows, Toothless' Saddle and Tail Fin, Dragon Scale Armor, Deathgripper Venom
Plants: Dragon Root, Blue Oleanders, Purple Oleanders Other: Yak Nog, Bork's Papers, The Book of Dragons (original, The Nine Realms), Hiccup's Prosthetic Leg, Astrid's Betrothal Necklace, Gobber's Peg Leg