User blog comment:Annabeth and Percy/Fourth Dragon Fight Club Match: Windshear vs. Barf and Belch/@comment-3230751-20170330032007/@comment-26100403-20170409180835

Toothless already beat a razorwhip in RTTE when the dragon hunters forced him to fight in arena battles. That was without being able to fly. Toothless also beat Sleuther and would have killed him if he hadn't learned not to kill unnecessarily. So Toothless would beat literally any other dragon he could possibly fight. In the air, he'd be even deadlier. He did beat the red death by lighting its insides on fire and making it explode. He also beat Drago's bewilderbeast, but that was on the ground. If this were matchup between Toothless and Windshear, Windshear would get destroyed, especially if Toothless went straight to alpha mode. The skrill is the only dragon that almost bested Toothless. In a real fight, Toothless would probably beat Cloudjumper, but Valka didn't let a fight happen so we'll never really know.