User blog:Leon Jung/I need some help

So I'd been wandering on the internet. I saw some gif of Skullcrusher and Cloudjumper, but I've never seen those videos before, it's like The Book Of Dragons short film for HTTYD2. There was Gruff, Stormfly, Grump, Toothless, too. I wonder if you can tell me what video it is.

Here are the links of the gif:

http://67.media.tumblr.com/75f6fac17f042f62d001a1cdfb1744fe/tumblr_ndurtkPsuN1t4wx8uo2_500.gif

https://www.google.com.vn/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=https%3A%2F%2Flh6.googleusercontent.com%2F-MNmTX94ccrA%2FVG_CzQmoTDI%2FAAAAAAAAApw%2FDA97HqPh81A%2Fw250-h230-no%2Ftumblr_ndr1jm7ZuQ1t4wx8uo2_250.gif&bvm=bv.128617741,d.dGo&psig=AFQjCNFCDAreF3DzPanA-MabpJi7d7-hhA&ust=1469850218717441

https://67.media.tumblr.com/b1f8ff005a5fe2efef7ecf1034e90d59/tumblr_ndy8fqHJzS1t4wx8uo1_500.gif

https://www.google.com.vn/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjhgdOO4ZfOAhWKHZQKHVbtDGAQjBwIBA&url=http%3A%2F%2F33.media.tumblr.com%2Ff558320868f09babb5723a60dc958e6f%2Ftumblr_nf759v6YpY1sgf7tzo3_500.gif&bvm=bv.128617741,d.dGo&psig=AFQjCNEFJ7pm5kwawDh0MxA8xbgUTlnggg&ust=1469850274723224

Please help me, I've never seen this video before.