Wyvern

Wyverns are long, white, oriental-dragon-like creatures which appear at certain heights on Hardmode (typically at or above the Floating Island level) and can even spawn directly above the start point of a map. The wyvern spawn rate increases the higher up you get.

The Wyvern attacks like a Devourer or Bone Serpent, making long, sweeping passes. Fighting them at high altitude and taking advantage of the lower gravity is useful for dodging, since they can do a lot of damage quite quickly. Weapons or Spells that strike a target multiple times (ex; Demon Scythe) are your best bet for fighting the Wyverns, as with any other worm.

Fighting the Wyvern
Fighting wyverns can be difficult as they deal respectable amounts of damage and are very fast. A wide variety of tactics are effective. The Clockwork Assault Rifle is extremely effective when coupled with the Rocket/Spectre Boots. With good armor and a few Ironskin Potions, a spear can also be quite effective. The Magical Harp is considered the best magic weapon to deal with the wyverns.

If you are in an enclosed space like a house, spamming a weapon which bounces off walls can prove quite effective since the wyvern will fly right through the walls of the house to attack you.

Note

 * If you are above or close to your house and are fighting a wyvern, and you use Magic Mirror to teleport back, the wyvern will follow you to your house/spawn point.
 * They tend to spawn rather close to housings(presumably so they target sky islands more). Those having structures in high altitudes before defeating the Wall of Flesh should consider moving to lower altitudes before activating Hard Mode spawns.
 * To make them have a higher spawn rate, make a sky bridge[] made out of pearlstone.

Trivia

 * Although the name "wyvern" refers to a wester dragon depicted as having two wings and two arms or forelegs, but no hind legs, Terrarian wyverns are shaped after eastern dragons originated in Chinese folklore, also know as 'lung dragons' in D&D. Because of their color, body shape and general style, Terrarian wyverns bear a close resemblance to several dragons from popular culture. Notable examples are:
 * Haku's true form, from the animated film Spirited Away.
 * Fuchur (known as Falkor in the English translation) from Michael Ende's "The Never Ending Story".

History

 * Early mentions:
 * Something unusual, something strange 22nd September 2011
 * Terraria 1.1 Trailer 25th November 2011