Paladin

Paladins are rare, resilient Hardmode enemies that spawn in the Dungeon after Plantera is defeated. They throw hammer projectiles rapidly that can pass through blocks and inflict extreme damage. Paladins only spawn in Dungeon areas with Brick Walls.

Paladins are immune to knockback, as well as the Poisoned, Venom, and Confused debuffs.

Tips
The paladin will not throw its hammer if you are close
 * Paladins are exceptionally tough enemies. Their projectile attack is unusually versatile for a non-boss enemy and inflicts extreme damage. A Paladin has more health than Skeletron, immunity to knockback and high defense, making it difficult to kill and dangerous to try to slip past or ignore.
 * Paladins are less likely to target players outside their line-of-sight, or players at higher elevations (it generally cannot fire above 45 degrees). They lack the ability to throw their hammers downward as well.
 * Fighting it in hallways is not recommended, as this leaves no room for dodging, and often leads to a quick death.
 * A Paladin's attack will be interrupted if it takes damage, making fast weapons more effective at keeping it suppressed.
 * The damage taken from touching a Paladin is much weaker than its thrown hammers.