Santa-NK1

Santa-NK1 is a Hardmode post-Plantera mini-boss that spawns during the Frost Moon event. When below half health, the face and beard of the Santa mask will be torn apart to reveal a rather morbid mechanical skull underneath.

Defeating Santa-NK1 will add 100 points during the Frost Moon.

Attacks
Santa-NK1 has four different attacks, all of which occur independently of each other:
 * Santa-NK1's chain gun periodically fires bullets at the player. Its rate of fire increases as its health lowers, going from 3.75/sec (initially) to 7.5/sec when below 25% health.
 * Santa-NK1 randomly drops large Santa-NK1 Spike.png spiked balls on the ground that deal very high damage. These increase in frequency as Santa-NK1's health drops.
 * Santa-NK1 will randomly fire a barrage of Missile.png missiles which can travel through blocks. These are fired at a constant rate of 5 per second. These barrages become more common as Santa-NK1's health drops.
 * Santa-NK1 will also randomly launch a barrage of Santa-NK1 Present.png presents high into the air which rain down via parachutes, causing contact damage to players. These travel through blocks, and are fired at a constant rate of 6.67 per second. These barrages also become more common as Santa-NK1's health drops.

All of Santa-NK1's attacks either increase their rate of fire or increase their chance of occurring as its health drops, as described above; the specific effects are listed in the following table. Note that these changes happen as Santa-NK1's health passes the listed thresholds, and are not continuous; thus, for example, its chain gun firing rate will be 3.75 bullets/second at 100% health and also at 75% health, but as soon as its health drops below 75%, the rate of fire will increase to 4.29/sec.

Tips

 * Players should note that his present launcher and rocket barrage attacks are highly inaccurate.
 * Using wings to fly over him back and forth will make his chain gun and the missile barrage harder to hit the player.
 * The Razorpine and Golden Shower is very effective against him, given the player has obtained these items. Hitting him first with the Golden Shower to lower his defense, and then fire Razorpine at him. This is highly effective with Spectre armor with the Spectre Hood as it fully heals the player no matter how low the player's health is.
 * This seems to be even more effective on the because the Spectre Hood still has its old stats, which increases magic damage, instead of lowering it.
 * is even more effective at lowering Santa-NK1's defense.

Trivia

 * The spiked balls can players in, due to their damage being . This is by far the most damage dealt by a single attack in the entire Frost Moon event; it is also stronger than most other bosses' attacks, even dealing higher damage per hit than the Moon Lord's Phantasmal Deathray.
 * "Santa-NK1" is a play on the portmanteau of Santa and Tank, "Santank," the name used when the enemy was first announced.
 * The image in the game files used for when the face is ripped off uses the name "SantaTank.png."
 * Its arm appears to be a large Chain Gun, an item which it sometimes drops.
 * The face and mask may be a reference to the "" film series, as the Terminator has a metal frame and an outside 'skin'.
 * It is one of the only three bosses whose map icon does not change after entering its second phase, the others being the Brain of Cthulhu, and the Queen Slime.
 * There is no Pumpkin Moon equivalent to Santa-NK1, unlike the other two Frost Moon bosses (Everscream and Ice Queen), who each have counterparts in the Pumpkin Moon event (Mourning Wood and Pumpking, respectively).