DreamWorks Animation has been absorbed by Universal Pictures, and their distribution deal with Twentieth Century Fox ends in 2017. Because of this, the film's release has been shifted up to May 18, 2018, and it will bring back some of the new characters such as the villain Drago, voiced by Djimon Hounsou.

According to We Got This Covered, Drago was portrayed as the main villain in the second film, but while his dragon perished, he managed to survive. The actor is also reportedly signed on to reprise his role, although it is unclear if he is going to be the main villain or if someone new will step in.

The report points out that executive producer Dean DeBlois said they are comparing Drago to the Emperor (Ian McDiarmid) from the "Star Wars" films. The Emperor was not present in the first film, he was teased in the second, and became the main villain in the third, "Return of the Jedi." This is the same direction DreamWorks is going with Drago except for the fact that he was prominently featured in "How to Train Your Dragon 2."

It is further stated that the film will see Hiccup (Jay Baruchel) as the leader of his tribe. This does not mean that his parents will now only have a small role. His mother, Valka (Cate Blanchett), is going to be in the film, and DeBlois also confirmed that Stoic (Gerard Butler) is returning as well.

Stoic died during the finale of the second film, and it is widely speculated his scenes in the third movie will strictly be flashbacks instead of being revived by some sort of magic.

It is uncertain if Eret, voiced by Kit Harrington, is going to make a return. Eret was portrayed as an antagonist, serving Drago, and while fans expect him to return, the character might not be present due to Harrington's schedule in filming "Game of Thrones."