King Slime is the easiest pre-Hardmode boss. Can be summoned with a Slime Crown crafted from 20 Gel and a Gold/Platinum Crown at a Demon or Crimson Altar. He teleports to the player, spawns Slime minions, and gets faster as his HP decreases. Use platforms to avoid him and ranged weapons are recommended.

The Eye of Cthulhu is typically the first boss new players encounter. It spawns naturally at night once certain conditions are met, or can be summoned with a Suspicious Looking Eye. It transitions between a passive eye form and an aggressive mouth form at 50% HP.

The Brain of Cthulhu is a Crimson-exclusive boss. Summoned by destroying 3 Crimson Hearts or using a Bloody Spine. Has two phases: first phase surrounded by Creepers that must be killed, second phase the Brain itself becomes vulnerable and teleports.

The Eater of Worlds is a Corruption-exclusive giant worm boss. It consists of multiple segments (Head, Body, Tail) that can each be damaged independently. When a segment is destroyed, the worm splits into smaller independent worms, making the fight progressively more chaotic.

Skeletron is the final pre-Hardmode boss guarding the Dungeon entrance. Summoned by talking to the Old Man at the Dungeon at night. Has a head and two hands — the hands have high defense and spin attack. Must be defeated before dawn or it becomes nearly invincible.

Queen Bee is optional, but her drops — Bee Gun, Bee Armor, Hive Pack — make the next few bosses way easier. She is farmable too, so kill her at least twice to get the full set.

Deerclops is a Don't Starve Together crossover boss. It spawns naturally during blizzards in the Snow biome at midnight, or can be summoned using a Deer Thing. It attacks with shadow hands, ice spikes, and debris projectiles.

The Wall of Flesh is the final Pre-Hardmode boss — kill it and your world changes forever. 8,000 HP in Classic (11,200 Expert, 14,280 Master), spans the entire screen in the Underworld, and moves faster as it loses health. This is a DPS race on a bridge you built yourself.

Queen Slime is an early Hardmode boss that can be summoned in the Underground Hallow. She is a large, pink slime creature that bounces around and summons smaller slimes to aid her in battle. Defeating her grants access to powerful equipment and materials.

The Twins are the most mechanically demanding of the three Mechanical Bosses — Retinazer has 20,000 HP with rapid lasers, Spazmatism has 23,000 HP with tracking Cursed Inferno. Kill Spazmatism first or die. Drops Souls of Sight and Hallowed Bars.

The Destroyer is the easiest Mechanical Boss and the best first kill. Its 82 segments share a single HP pool, making piercing weapons deal multiplied damage. Daedalus Stormbow + Holy Arrows melts it in under 2 minutes. Drops Souls of Might and Hallowed Bars.

Skeletron Prime is the most heavily armed member of the Mechanical Trio. Equipped with four distinct mechanical limbs (Laser, Cannon, Saw, and Vice), it presents a chaotic and challenging battle. Players must defeat it before dawn, or it will transform into an invincible guardian and instantly kill the player.

Plantera is the gatekeeper of late Hardmode. Kill her and you unlock the Jungle Temple (Golem), the post-Plantera dungeon (Paladins, Tactical Shotgun, Sniper Rifle), and the Cyborg NPC. She spawns when you break a Plantera's Bulb in the Underground Jungle — but only after all three Mechanical Bosses are dead. Phase 1 defense is 36, Phase 2 drops to 10, and she drops one of 8 weapons at 12.5% each (1.4.5). Build a big arena or she will corner you.

Golem is a powerful Post-Plantera boss summoned inside the Lihzahrd Temple using a Lihzahrd Power Cell at the Lihzahrd Altar. After defeating Plantera and gaining access to the Jungle Temple, players must face this multi-part stone guardian with its detachable head, deadly fists, and devastating fire attacks.

Duke Fishron is the most challenging optional boss in Hardmode — 60,000 HP, three-phase transformation, and Phase 3 invisible teleport dashes. He can be summoned any time in Hardmode, but his real difficulty slots in after Golem. 1.4.5 adds the Electric Eel weapon and shifts drop rates from 1/5 to 1/6. His drops carry you all the way to Moon Lord.

Empress of Light is Terraria's most spectacular boss — 70,000 HP, rainbow bullet-hell patterns, and a daytime-only instant-kill mode that drops the Terraprisma. She can be fought any time after Plantera, but her real reward demands a flawless daytime kill.

The Lunatic Cultist is a Hardmode boss that appears at the Dungeon entrance after Golem has been defeated. He has no summoning item - instead, defeating the four Cultists at the Dungeon entrance triggers the fight. Defeating the Lunatic Cultist initiates the Lunar Events, spawning four Celestial Pillars across the world.

Moon Lord is Terraria's final boss — 145,000 combined HP across three True Eyes and a core, Phantasmal Deathray hitting 150+ per tick, and a 10-weapon drop pool where you get 2 non-duplicate weapons per kill (~20% each). Spawns after clearing all 4 Celestial Pillars or via Celestial Sigil (12 of each fragment).

Pumpking is the final boss of the Pumpkin Moon event, spawning from Wave 7 onward with 22,000 HP. It flies aggressively and attacks with spinning scythe arms and flame scythe projectiles. Drops some of the best weapons in the game: Horseman's Blade, Bat Scepter, Raven Staff, and Candy Corn Rifle.

The Ice Queen is the final boss of the Frost Moon event, appearing from Wave 11 onward. She hits like a truck — 84 base damage with ice bolt barrages, spinning dive attacks, and frost wave rings. Reaching her is the goal of every Frost Moon run, and her drops (Blizzard Staff, North Pole, Snowman Cannon, Reindeer Bells mount) are some of the best items in the game.

Mourning Wood is the first mini-boss of the Pumpkin Moon event, spawning from Wave 4 onward. It rains Greek Fire from above and shoots flaming projectiles along the ground. Farm it for Spooky Wood and the Necromantic Scroll -- two of the best summoner progression items in the game.

Santa-NK1 is a mechanical Santa Claus tank that shows up from Wave 7 in the Frost Moon. 120 base damage, 56 defense, 35000 HP — this thing is built like a brick wall. It fires chain gun bullets, homing missiles, and explosive presents. The 56 defense is the real problem: you need armor penetration or raw damage to chew through it. Drops the Chain Gun (one of the best ranger weapons in the game) and the Elf Melter flamethrower.

Everscream is the first mini-boss of the Frost Moon event, spawning from Wave 4 onward with 13,000 HP and 38 defense. It launches ornament projectiles and fires rapid pine needle sprays. Drops the Razorpine (one of the highest DPS mage weapons), Christmas Tree Sword, Festive Wings, and Christmas Hook.

Betsy is the final boss of Old One's Army Tier 3 and the hardest challenge the event has to offer. She flies overhead spewing fire that leaves burning trails on the ground, charges across the arena, and can shred your crystal's HP if you lose control. Her drops — Flying Dragon, Betsy's Wrath, Aerial Bane, and Sky Dragon's Fury — are some of the best weapons before Moon Lord.

The Martian Saucer is the deadliest enemy in Martian Madness and the reason you farm this event. Phase 1 has 4 turrets (minigun, rocket, laser) that chip you down. Phase 2 fires a death ray that deals 150+ damage per tick — instant death if you don't move vertically. The payoff: Cosmic Car Key (UFO mount), Xenopopper, Influx Waver, and Laser Machinegun.

The Solar Pillar is the hardest of all four Celestial Pillars. Crawltipedes one-shot airborne players. Selenians reflect projectiles back at you. Stay on the ground, use melee or non-reflectable attacks, and clear 100/150 enemies to break the shield. Drops Solar Fragments for Solar Eruption, Daybreak, and Solar Flare Armor.

The Vortex Pillar is a mid-difficulty Celestial Pillar focused on ranged enemies. Storm Divers rapid-fire bullets at you, Alien Hornets shoot homing projectiles, and Alien Queens spawn more hornets. Build multi-layer platforms, dodge Storm Diver fire, and clear 100/150 enemies. Drops Vortex Fragments for the Vortex Beater, Phantasm, and Vortex Armor.

The Nebula Pillar spawns teleporting magic enemies that are hard to track. Brain Sucklers attach to your head and deal continuous damage, Nebula Floaters teleport and fire magic bolts, and Predictors shoot homing projectiles. Build an open arena with clear sightlines and kill 100/150 enemies. Drops Nebula Fragments for Nebula Arcanum, Nebula Blaze, and Nebula Armor.

The Stardust Pillar is the easiest Celestial Pillar. Star Cells split into smaller cells on death that regrow if not killed quickly, Flow Invaders fire slow projectiles, and Stargazers shoot powerful laser beams from range. Build 2-3 platform layers, kill small Star Cells immediately after splits, and clear 100/150 enemies. Drops Stardust Fragments for Stardust Dragon Staff, Stardust Cell Staff, and Stardust Armor.