That's not a dragon, it's the Midguard Serpent.
"The serpent grew so large that it was able to surround the earth and grasp its own tail.[2] As a result, it received the name of the Midgard Serpent or World Serpent. When it releases its tail, Ragnarök will begin. Jörmungandr's arch-enemy is the thunder-god, Thor. It is an example of an ouroboros."
Time for the Hammer of Thor pic from Q?