Coretaur

Coretaurs are Pre-Hardmode enemies that spawn in the Underworld after the Eater of Worlds or Brain of Cthulhu has been defeated.

Attacks
Their attacks include:
 * Hopping toward the player, much like a Biome Mimic would.
 * Performing three rapid dashes, during which it can also jump extremely high.
 * Periodically shielding itself and remaining stationary, during which it becomes invincible to attacks. In Expert mode, it will reflect players' projectiles that can damage players.
 * Performing a "pound" attack, whereby it leaps into the air above the player and swiftly drops down, like a Giant Tortoise. However, Mimics can travel through blocks during this attack, unlike Giant Tortoises.
 * If the player attempts to escape, the Coretaur dashes after the player at high speed (slightly over 51 mph). This attack can also travel through blocks.

Trivia

 * Coretaurs are based off of s from Greek Mythology.