Watch How to Train Your Dragon: The Hidden World (2019) HD Full Movie Free on SolarMovie. Watch How to Train Your Dragon: The Hidden World (2019) online free. When Hiccup discovers Toothless isn't the only Night Fury, he must seek "The Hidden World", a secret...When Hiccup discovers Toothless isn't the only Night Fury, he must seek "The Hidden World", a secret Dragon Utopia before a hired tyrant named Grimmel finds it first.