Pigron

The Pigron is a Hardmode enemy found in the Ice biome when it is overlapped by Underground Hallow, Underground Corruption, or Underground Crimson. It comes in multiple colors, depending on which biome it spawns in.

Pigrons have a special ability to become transparent and nearly invisible, allowing them to fly through solid blocks. As a transparent Pigron starts to attack, it will become visible again. When it starts moving towards the player, it occasionally makes an audible growl. If it is in its solid, visible state and is blocked by solid blocks on its path to the player, it will become transparent again to pass through them.

Tips

 * Utilizing the Hunter Potion makes finding and dispatching a Pigron much easier, as it glows when it would normally be nearly invisible.
 * Pay attention for growls while in Ice biome, since Pigrons will usually be heard sooner than they're seen, and the sound they make is unique.

Trivia

 * The name is a portmanteau of the words "Pig" and "Dragon". This was confirmed by Cenx in the IRC.
 * Pigrons bear striking resemblaces to Pommy Dragon from the Bomberman series. It is unknown if this was intended or not.
 * There is a discontinued plush Pigron sold in real life by Toynk Toys, based on its purple appearance in the Underground Corruption.