Atlas

Atlas is a Hardmode enemy which spawns on the Surface Astral Infection biome. It is initially idle, in which it stands still and occasionally turns around. If it notices the player, it will walk slowly towards them, attempting to jump over any obstacles in the way. When Atlas gets close enough to the player, it will uppercut them with its big arm and launch them far away, after which the attack will enter a short cooldown. If it loses sight of the player for long enough, it will return to its idle behavior.

If the Lunatic Cultist is defeated but Astrum Deus has not yet been defeated in the current world, Atlases will spawn three times as often.

Trivia

 * In Greek mythology, Atlas is the Titan of endurance, strength and astronomy who was meant to hold up the celestial heavens for eternity.