To Tame a Titan! is a short story of sorts published on October 1, 2014 by DreamWorks on their How To Train Your Dragon movie Facebook page. It was also published on Tumblr. According to the notes that appear with this short story, it takes place before the HTTYD 2 movie.
The story is divided in 6 parts. At the end of each part readers were presented with two scenarios and were asked to choose one in the comments section. The readers choice was taken into account when publishing the next part. Each part was also released with an original artwork illustrating the story.
To Tame a Titan! features a Titan Wing Hideous Zippleback, which the twins name Sparks and Spew. Sparks and Spew threaten Berk because the two heads cannot come to a decision as to what to eat. The twins solve their dilemma by creating a 'coin' to flip. One side is etched with waves, the other with a flame. Sparks and Spew seem to understand its purpose and fly away with it.