Okay, so I need to write an article about the main characters in How to Train Your Dragon, specifically focusing on Hiccup and Toothless. Let me start by recalling the key points from the context provided. The user mentioned Mason Thames and Nico Parker in outtakes, so maybe they're the live-action actors. The overview talks about dragons and their riders, and there's a mention of different classes in the HTTYD universe. The user also provided some hashtags related to the movie and Universal Pictures. First, I should structure the article with natural headings. The main sections would probably be an introduction, sections on Hiccup and Toothless, their relationship, maybe other characters like Astrid or the dragon classes, and a conclusion. I need to make sure the article is between 600-900 words. Wait, the user mentioned "classes in the universe of How to Train Your Dragon." That might refer to the different types of dragons, like the Night Fury, Deadly Nadder, etc. I should include that information about dragon classes, explaining how they fit into the story and Hiccup's role as a rider. I need to avoid unsupported claims. So, I can't say things like "Hiccup is the best dragon trainer ever" unless there's a source. I should stick to facts from the movies. Also, the user wants natural headings, so maybe use h2 and h3 tags as in the example. The user provided some context lines that might be part of a larger article, but I need to make sure my article is original. Let me check the requirements again: 600-900 words, natural headings, avoid unsupported claims, no markdown, just HTML tags. I should start with an introduction about the main characters, Hiccup and Toothless, their significance in the story. Then discuss Hiccup's character development, his traits that make him a good dragon trainer, maybe his relationship with his father, and how he changes the world. Then talk about Toothless, his species, abilities, and their bond. Then maybe a section on other characters like Astrid, Gobber, and the dragon classes. Finally, conclude with their impact on the story. I need to make sure to mention the live-action actors, Mason Thames and Nico Parker, since they were in the context. Maybe include a note about the live-action adaptation and how the characters are portrayed there. Also, the user mentioned "outtakes" where the actors "crack up," so perhaps a brief mention of the behind-the-scenes aspect, but not sure how to fit that in without making it off-topic. Maybe in a section about the live-action film's production or the actors' performances. I need to check word count. Let me outline the sections with approximate word counts to stay within 600-900 words. Introduction: 100 words. Hiccup: 200. Toothless: 200. Other characters and dragon classes: 200. Conclusion: 100. That's about 800, which fits. Make sure to use the keywords naturally, like "How To Train Your Dragon main character," and include the hashtags at the end as per the context. Avoid markdown, use HTML tags like h2, p, ul, etc. Wait, the user's context includes some lines that might be part of a larger article, like "Overview: This video features all the dragons and their riders..." Maybe that's from a different source, but I shouldn't copy it. I need to rephrase and create original content. Also, the user mentioned "A while back, we tackled the..." which might be a previous article, but I can't reference that. Focus on the main topic. Check for any unsupported claims. For example, don't say "Hiccup is unique" unless it's stated in the movie. Instead, explain his traits as per the story. Now, start drafting the introduction. Then Hiccup's section: his personality, how he's different from other Vikings, his empathy towards dragons, his role as a dragon trainer. Maybe his relationship with Toothless starts as reluctant but grows into trust. Toothless's section: Night Fury characteristics, abilities like speed,