What i find most tender in Toothless is the incredible expressiveness of his big eyes. Remember when he sits like a dog and stares Hiccups with that so delicious seriousness?

Yes~! Thats was one of my favorite parts XD

I found so touching when Hiccups gives the fish to the small dragon and it curls to sleep beside him! It reminded me of my cat!
Seeing again the movie, it is patent Toothless is incredibly agile and maneuvarable in flight, almost like a living fighter. His wong movements are excellently done and even I could discern one or two actually used by falcons in diving.
The race grazing the sea also calls to mind Neverending Story, when Bastian and falcor race across the sly.