Director Dean DeBlois announced that "How to Train your Dragon 3" will be his last involvement with the Dragons. He also revealed that it would be an emotional journey for Toothless and Hiccup, and would probably be the last time that the dragons can be seen.

There have already been previous rumors that "How to Train your Dragon 3" would be the last of the franchise. It will be a tear jerking moment as DeBlois reveals that Hiccup and Toothless might be parting ways. There are eight original books written by Cressida Cowell, but DeBlois thinks that doing a trilogy was enough to better tell the story. There are talks about a possible sequel, but that would depend on the discretion of DreamWorks Animation.

The composer of the series, John Powell, suggested on splitting "How to Train your Dragon 3" in half, making the franchise a quadrilogy. According to Slashfilm, his suggestion has yet to be discussed by the creator and the producers. Meanwhile, DeBlois has set the expectation that he was considering Cowell's suggestion, and would make sure that the animation sticks to the plot of the novel.

With regard to the release date, "How to Train your Dragon 3" has been moved to May 18 instead of June 29, 2018. According to Comic Book, the move was to ease up the tension between Fox and Warner Bros., as it is known that the two have been competing in terms of animated films. The release date now occupies the original release date of "The LEGO Movie," which has been moved to Feb. 8, 2019.