Two worlds ?Completed?

We had read every single dragon. Stormfly​ and Toothless didn't match any of them. I sat with Astrid and the gang while the dogs played.

"Ok, so for Stormfly, I say Razorwhip​, Deadly Natter, sandwrath, or Monsters Nightmare." Tuffnut said.

"No. Definitely not a Monsters Nightmare." Ruffnut said.
"Your right, I mean, we can't have two Hookfangs, that would need up the rhythm." Tuffnut agreed.
"Rhythm?" We asked.
"Yous see, my friends, all of our dogs our different dragons...Partly, Barf and Belach count as one, but Stormfly and Toothless, are different."
"...Ok..." I said.

"I know! Their speed!" Astrid said.
"Ok, I always have speed trackers on me, hold them still?" Fishlegs asked.

We held our pups still. Well, partly. Toothless was playfully nipping at my hand while I laughed and Stormfly kept licking Astrid's hand.

Once they were attached, we let them go.

"Stormfly​! Toothless!" Astrid said.

They looked.
"Ready?" I asked.

They barked and got ready to run.
"Set..." Astrid said.
"Go!" Everyone said.

They took off across the filed, incredibly​ fast. Stormfly closed in on Toothless but came up short. We ran down the field with the others and third dogs. Stormfly and Toothless were laying next to each other, panting. I took off the speed tracker and handed it to Fishlegs as Astrid did.
"Whoa, Stormfly is definitely a Deadly Natter." Fishlegs said, obviously impressed.

Astrid smiled and cradled the exsausted pup as I did mine.
"Um.... Hi-Hiccup?" Fishlegs said.
"Yeah?" I asked, staring to worry for Toothless​.
"Toothless is a...A..."
"What? What is he?" I asked, getting impatient.

Astrid looked at Toothless I'm worry.
"Toothless is a ... Nightfury."

We gasped.
"Nightfury?!?" I asked as the two pups fell asleep.