I suggest listening to 'time of dying' 'hurricane' and 'Bring me to life' while reading. they go petty well with it. I do not own HTTYD, just their shared AU back story.
Stroik turned as his wife gave a cry of pain. He rushed to her, just as his son was born. "Oh, Hiccup." He murmured, looking into the boy's hazel eyes. His wife gave another cry. Twins? he thought, staring as a little black dragon, a night fury, rolled out. The wonder and pride he felt turned to terror. Vira smiled. and held the thing, he dared not call it his son, to her breast.
"Stroik, bring me Hiccup." He shook his head, holding tighter to the boy. She give a soft sigh. "Toothless, will you get your brother? Be carefull with him, now." The dragon, Toothless, pulled away and let his teeth back down, nodding. He flew to his father and brother. His dad held Hiccup closer, as if to shied him from his twin. Toothless let out an annoyed huff, and snatched Hiccup. Striok's eyes widened. Did he imagen it or did a dragon have the same colored eyes as his son?
As soon as he was in the air, Hiccup started crying. Toothless gently laid his brother in his mom's arms. "Don't cry, I won't hurt you." he reassured the little boy in garbled baby dragon talk, nuzzling him affectionately. His mom smiled as Hiccup calmed down. She could not understand Toothless, but she had a good idea of what he said. "Who, who are you?" Hiccup asked in baby talk. Like with him, Toothless understood. "I'm Toothless! We're brothers!" He exclaimed kneeling playfully.
"I'M Hiccup!"introductions over, Hiccup reached to playfully hit his shoulder. That night, both babies laid side by side in different cradles. "Toothless?" Hiccup asked, crawling to the side. His brother stirred and looked at him. "Yes?"
"We will always be brothers,right?" Toothless gave a small smile. "Right." He did not know how wrong he was.