I don't really see what the Leviathan can do to Smaug. It seems the main method of attack for the Leviathan is to just ram in to things... and I doubt it's fast or agile enough to ram Smaug.
While that armor might present challenges for Smaug, he does have more options at his command: claws, teeth, fire, smarts, etc.
I'd rather put my money on the guy who can actually hit the other guy instead of the guy who just tanks everything.
Originally posted by Lestov16
Leviathan takes this. It was so durable that it was smashing through buildings and IM's entire energy output couldn't future it's external shell. Smaug is too big to pull off what IM did and will likely get crushed. Leviathan for the win.
And how exactly do you think the leviathan will take down Smaug? Headbutt him?