Here are mine:
The issue I see with that is that (thankfully) HTTYD dragons don't
speak. So while I would love to get Toothless' backstory, it would be hard to do. It would have to be something like the old silent movies, except less, since those still put "spoken" text on the screen. Documentary style
could work, but I don't think that would feel right.
ALTHOUGH! They
could frame it as Toothless (with Hiccup) finding something from his past somewhere (Dark, but something like his brother's skull, perhaps?), inciting them to try and track down the rest of his past. The show could then use
many flashbacks along the way to tell the story. Like, (going with the skull idea), if they find that with a hole in it and Toothless just gets a sad look before insisting on taking off and heading whereever, that's confusing to the audience and open for any number of interpretations.
BUT, if they find the skull and we get a flashback to Toothless and another Night Fury flying together before a hunter's arrow pierces the other's head and takes him down, even if we don't at that point know who the other Night Fury was, we now have an understanding and can make sense of what's going on when Toothless does as I said earlier. And we know Hiccup's clever enough and knows Toothless well enough to piece together the story himself as they find more pieces of it.
...How and where do I pitch this concept to DreamWorksTV?