FWIW, Toothless/The Night Fury design was changed from the books to the movies, as I understand.
how to train your dragon - Why was Toothless toothless? - Science ...
In How to Train Your Dragon, Hiccup is sitting on a rock drawing a picture in the sand with a stick. The picture he draws is clearly of Toothless - the Night Fury dragon. Toothless looks at the ima...
However, Toothless had already been in the Hidden World for at least a day at that point - he leaves with the Light Fury, they go to the Hidden World, then we see Hiccup at night, and then during daylight Hiccup and Astrid set off in search of him. We do not know if this is the next day, or 2 days later, or even a week.
In Harry Potter, the publican of the Leaky Cauldron is described as toothless. Why is this, given that (as Hermione shows) magic can regrow teeth?
In the hidden world scene ‘king’ Toothless calls out to the dragons of the hidden world. When the dragons respond next to the Light Furies, we see a Bewilderbeast that looks EXACTLY like Drago’s Bewilderbeast from HTTYD 2.
Why is there a Bewilderbeast responding to king Toothless in HTTYD 3?
After the events of the second movie, Toothless is the alpha dragon - all other dragons will follow his will. Grimmel captured Toothless and the Light Fury, using her as leverage to force Toothless to do his own bidding, which was basically to command the dragons to leave the Berkians.