Changewing Island is a nesting ground and home for the Changewing dragons.
This forested isle hides many surprises in its thick branches — from the acid-spitting, chameleonic Changewings to their iridescent eggs nestled on the boughs. The only safe part of this island is the sky above it, where Changewings are unable to blend into their surroundings. The island is covered in trees, and the Changewings lay their eggs in the branches.
Changewing Island. Ah, such a peaceful place. Except for all the Changewings, of course.[src]
— Fishlegs describing Changewing Island
Three years later, the teens went to Changewing Island to search for glowing Changewing acid to light up a new lens they found in the episode "Night of the Hunters, Part 1". They then encountered Tuffwing, a Changewing that Tuffnut managed to capture it get the Changewing acid. Eventually, they used the acid on Snotlout's helmet to power up the Dragon Eye.