Disclaimer: I do not own How to Train Your Dragon or Percy Jackson and the Olympians.
It was only when they were teleported to Camp Half-Blood/Camp Jupiter that they realised their parentage. At least, all of them except for Hiccup did.
Hiccup, despite his differences, had what was essentially dual godly parentage, and both the Athena and Hephaestus Cabin fought to gain his attention. Hephaestus Cabin succeeded for about an hour with their forge and advanced equipment, but then Athena Cabin managed to snag him back with the blueprints they had.
Percy shook his head. Leo and Annabeth, the Cabins' head campers, looked amused as Hiccup was literally pulled from each Cabin. Fishlegs and Astrid (their half-siblings), also looked on in amusement.
Hiccup, being a Viking, son of a chief and his mother, a friend to the dragons who knew more about them than any other (who sometimes seemed more dragon than human), tamer of the Nightfury, and blessed by Athena and Hephaestus, was a powerful being.
His dragon, of course, refused to leave his side, and watched curiously, crooning in concern as he watched his friend being dragged here and there.
Annabeth watched the creature with fascination. "A Nightfury."
Percy sighed. "Please don't bore Hiccup with a long lecture about the Nightfury."
Annabeth raised an eyebrow at him as Percy smirked. They turned back, laughing as they saw Toothless snag Hiccup, and both of them went flying up into the sky. Hiccup had accepted the status of the Olympians and demigods very easily, but his friends didn't. They had been raised to believe in only Norse Gods, after all.
Of course, Snotlout was pleased to see some other demigods who could fight like him, but he was still slightly uncomfortable.
It was because, Astrid later told them, that Hiccup's mother, Valka, (who had come with them and was now talking with Chiron, oh wait. She was now arguing with Mr. D about Hiccup. Gods, that woman was fierce when it changed to her son) was very open-minded to things, and so was he. Especially after they both helped the dragons and changing some of the most stubborn people in the archipelago's minds about their former enemies.
Valka got along with most of the people in Camp Olympus well, and her dragon became more comfortable around the demigods. But it was always on alert whenever Valka disappeared from view and would try to find her, though it would stay on one spot if Valka specifically asked it to.
Toothless was a different matter. He didn't stay where Hiccup told him to stay. Instead, he followed Hiccup everywhere he went, and even slept on the roof of the Cabin that Hiccup was staying in (In the end, Hiccup had had to stay in the Big House. The other Cabins Hiccup tried to sleep in were destroyed by Toothless).
Jason sighed. "Are you sure that they can help us defeat this Drago and Kronos?"
"Yes." Rachel didn't even turn to them as she answered. And she now pointed at Hiccup. "And he will be the one to kill them."
AN: And that's the last of it…wanted to have a chapter when they are all together. Just so we're clear, this is sometime after HTTYD 2, and after HoO. Might go into a deeper and more developed plot when I feel like it, but for now, I'm satisfied. Thank you all for reading!