Djimon Hounsou would often do vocal exercises to prepare for his voice acting. One of these was a loud, terrible scream. Dean DeBlois liked it so much that he decided to use it as Drago's cry to summon his dragons.
Dean DeBlois asked Cate Blanchett to play the role of Valka during the 2011 awards season where Dragon Trainer (2010) was being campaigned for Academy Award recognition. "I told her that I had written the part for her in How To Train Your Dragon 2. And she smiled, saying that the (original) movie was 'a big hit in her household with her three boys,'" said DeBlois. "I told her about the character, and I could see it blossoming in her mind." DeBlois wanted Blanchett to play Valka because he knew she could strike the right balance of "rich and commanding," mixed with a sense of "regret and vulnerability" that the part called for.
The first DreamWorks Animation film to use its new animation and lighting software through the entire production. Programs named "Premo" and "Torch" will allow much more "subtlety, in facial animation, the sense of fat, jiggle, loose skin, the sensation of skin moving over muscle instead of masses moving together." Dean DeBlois said, "I think the film looks a lot better than the first. In addition, our film is the first to showcase a whole new generation of software that has been developed at DreamWorks called Apollo. In past versions, if you wanted to do something as simple as arch an eyebrow, you would have to select the eyebrow from a menu and input what degree of arch you would want, enter that numerical amount, and wait for that to render," whereas the new system allows them to work in a much more intuitive way, using a stylus and touch-sensitive Cyntiq monitor to grab and manipulate the characters, which now render in real-time. "It allows animators to go back to working with their hands."
The song "Into a Fantasy," which is heard during the end credits, was written and performed by Alexander Rybak, who also provides the voice for Hiccup in the Norwegian version.
The first DreamWorks Animation film to win a Golden Globe award for Best Animated Film.