Squid

Squids are mentioned animals from which vikings get ink.

Description
Squid are cephalopods of the order Teuthida. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squids have eight arms arranged in pairs and two, usually longer, tentacles.

Function
Squids are wrestled by vikings for ink. Trader Johann said that he wrested a giant squid himself.

In reality, squids are also used as food.

Dragons: Riders of Berk
"Oh, that's pure squid ink, Hiccup. Wrestled from the colossal squid of the Northern waters."

- Johann to Hiccup

Dragons: Defenders of Berk
"Ten summers ago, deep under the currents of the Northern Waters, I was staring directly into the black eye..."

- Johann's story about he and the colossal squid