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.

It is one of the few enemies that can be detected by the Lifeform Analyzer.

Tips
My name is Jeff
 * 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.
 * A Paladin will not throw its hammers if you are close to him. A good strategy is to stay as close to it as possible while hitting it with any kind of melee weapon. A sword that allows you to attack in the opposite direction of where you're going, such as the Terra Blade, can be very useful. Yoyos are also very useful.
 * Another strategy is to create a small hole in the walls of the dungeon close enough so that the Paladin won't throw its hammers. Then, use a Nimbus Rod. The Paladin will continually take damage while the player waits. Note this may take a while.
 * Paladins are less likely to target players outside their line-of-sight.
 * Fighting it in smaller hallways is not recommended, as this leaves no room for dodging, and often leads to a quick death. If you were to fight a Paladin in a longer, two-way corridor, you may be able to kill the Paladin by continuously attacking as you back away from it. This can still be dangerous though, as any additional enemies that sneak up from behind can worsen the situation.
 * 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 weaker than its thrown hammers, unless in Expert mode.