Thorium Mod Wiki
The Grand Thunder Bird
The Grand Thunder Bird
The Grand Thunder Bird.png
AI TypeThe Grand Thunder Bird AI
Damage20 / 30 (melee)
60 (dash)
40 / 80 (lightning barrage)
30 / 60 (lightning shot)
40 (tornado)
Max Life1500 / 2000
KB Resist100%
Immune toCrowd Control.png
Coins5000*50 Silver Coin.png

The Grand Thunder Bird is the earliest boss available in the Thorium Mod, summoned by firing a Storm Flare from a Grand Flare Gun in the Desert during the day. It is considered the weakest boss of both the Thorium Mod's and vanilla bosses; however, it may still prove to be a challenge for unprepared players. The following are some hints, tips, and strategies to help defeat it. This bosses attacks are rather easy to dodge, but do quite a bit of damage still. A Cloud in a Bottle might be necessary. This boss drops various items, all listed on the side of this page.

Terrain Preparation[]

As the movement options for this point of the game are limited, a good strategy for this fight is to build a 100-120 block wide section of platforms with two levels, so that you can drop down to the lower platform when the Grand Thunder Bird fires lightning bolts, and the tornadoes will not affect you. In addition, when the Grand Thunder Bird charges at you, you will be able to easily drop down or jump up to another level. Additionally, Campfires provide increased life regeneration to nearby players, so you should include at least one in the arena near the middle.

Gearing Up[]


Due to the simplicity of the encounter, only basic armor is needed. Examples of such sets include Iron armor or Lead armor, as well as Cactus armor or Icy armor. Having at least 200 life will also help greatly.

If you are playing as a Mage, the Silk armor provides minor benefits to the player's magic capabilities. While the specific helmet makes little impact, the Silk Hat's increased magic damage may be preferable if you already have a decent amount of mana. Otherwise, the additional 20 maximum mana from the Silk Cap may be better for allowing more attacks before having to regenerate.

If you are playing as a Summoner, the Living Wood armor is the only armor available at the start of the game to provide bonuses for the class.

If you are playing as a Healer and were able to encounter a Blood Moon before combating The Grand Thunder Bird, both the Novice Cleric armor and Ebon armor sets will be available. The Novice Cleric set provides more healing bonuses compared to the increased radiant damage bonuses of the Ebon armor, so the choice should be based on if the healer wishes to focus more on healing allies or supplying more damage.

If you are playing as a Bard, the Crier armor is the best armor available for this stage of the game, being easily acquirable and providing bonuses for the class.


Accessories that increase the player's jump height, such as the Cloud in a Bottle, Blizzard in a Bottle, Turbo Boots, or Shiny Red Balloon can be helpful to rapidly dodge the boss' charges. Hermes Boots, Sailfish Boots, or Flurry Boots are useful to outrun the boss' feathers and bolt strikes, as well keeping it from sticking above you.

A Metallurgy Shield provides additional defense and life shield during combat, which may be helpful if you were unable to locate any Life Crystals before the fight. An Iron Shield or Lead Shield should suffice.

In a similar manner, having a Ring accessory would provide a minor buff to a certain attribute. However, some rings' availability may be much rarer than others, such as Amber or Pearl Rings, requiring use of an Extractinator or finding one in a Scarlet Chest. The Crietz is another fantastic accessory that can cause a notable spike of damage whenever you land a critical strike, and the downward angle the sparks take can potentially help against any hatchlings.

Equipping a String will increase the maximum distance a Yoyo can travel, which makes it easier to attack the boss should you plan on fighting with melee weapons. Though not recommended, if you are planning on using a Spear, a Silver Spear Tip will give a weak ranged option against the boss, which may be helpful during certain dangerous attacks.

If you happen to find a Living Wood Sap, it provides additional minion damage and knockback, which may be helpful if you are using summoning weapons.

A Wreath increases the velocity of throwing weapons by 10%, making it easier to hit the boss.

If you are a Healer, a Head Mirror and a Life Gem, should you manage to collect the materials, provide healing bonuses to both the healer and their targets.

If you are playing as a Bard, some options that increases the player's playing capabilities include Music Notes, Fan Letter, and High Quality Reed, should you happen to obtain some Dynasty Wood from the Traveling Merchant.


In general, it is recommended to use long-ranged, piercing weapons against The Grand Thunder Bird, as it hovers above the player for most of the fight, making close combat difficult.


Due to it staying above the player for most of the fight, melee combat is impractical with the exception of certain weapons.

Broadswords, while generally limited to clear out hatchlings, have a special property – if the Grand Thunder Bird is hit with a sword mid-charge, it will be stunned for a few seconds, allowing for a number of free hits. Additionally, it will take four times damage from swords in that time, meaning it is always advised to carry a sword for this encounter. While any sword will work for this purpose, the Ocean Slasher has autoswing and has a chance to inflict the powerful Gouge debuff, making it a good choice.

Using a broadsword capable of firing a projectile is highly recommended for this fight, as it allows for a steady stream of damage. However, at this point of the game the only swords with this capability are uncommon to come across. The Ice Blade is found in the Ice biome while the Starfury can be found within Floating Islands.

Spears are not particularly useful, but should you lack any other option, using one while having the Silver Spear Tip equipped will allow a decently-ranged projectile to attack the boss and its hatchlings with. Some options include the Trident, the Ice Lance, or the Ocean Polearm. The Swordfish's fast speed in particular is especially good with the Silver Spear Tip, as it fires every time you thrust the spear, and it does high damage.

Similarly, thrown Flails such as The Snowball or the Ball O' Hurt, while excelling at defeating hordes of hatchlings, will fall through the platform you will be likely fighting on, leaving you vulnerable for an extended time. Launched Flails, however, are worth considering as a sidearm as they are capable of decent damage at certain points of the fight. Unfortunately, only two options are available in Pre-Hardmode: the Chain Knife and the Whip, both of which you are unlikely to have at this stage of the game, so you should only consider this if you happen to have one of these.

Boomerangs are decent ranged options to throw once in a while. While the Cold Front is usable, it would be better to look for an Enchanted or Ice Boomerang for its longer range.

The best melee option alongside Swords are Yoyos. With the extended range from a String, they are capable of hitting the boss as it hovers above the player, and deals high damage while waiting for The Grand Thunder Bird to charge. While most of the available options are difficult to obtain, including Rally, Red Hourglass, or Amazon, you should only consider using the Wooden Yoyo if you are familiar with the boss's attacks, as its range is too short to hit the boss reliably, even with a String equipped.


Bows are the main ranged weapon at this point of the game. Some good options include Iron Bow or Lead Bow, Frost Fury, and the Coral Crossbow. As for ammunition, Ocean Arrows are a fantastic option for its piercing property, allowing the player to easily deal with the boss' hatchlings. The Gouge debuff additionally helps against the main boss. Alternatively, Jester's Arrows' faster velocity makes it easier to attack the boss, while Flaming or Frostburn Arrows inflict debuffs to deal damage over time.

At this point of the game, Guns are also an option, but lack the piercing options bows have. However, they are better at attacking the main boss itself. Options include the Musket or The Undertaker.

Aside from bows and guns, the Snowball Cannon is another very powerful choice. While the Snowballs it fires are unable to pierce, they are have notably high damage and decent velocity, all while being extremely easy to craft in large quantities. In addition, the weapon can automatically fire, reducing the need for constant button clicking many other weapons at this point require.


The Ice Cube is a great option, as it is unaffected by gravity, can pierce once, and inflicts Frostburn against enemies. If you are using the Ice Cube, try to make vertical pillars of blocks that the cube projectiles can slide on for more accurate shots. Alternatively, if you happen to collect enough Gems, a Gem Staff is another option against the boss for many of the same reasons as the Ice Cube. You should aim for an Opal or Onyx Staff at minimum before the fight, but a Sapphire or Emerald Staff would be preferable.

Of the nine bolt-style magic spells, the best options for the encounter are Ignite, Poison, Freeze, Pierce, and Siphon. Ignite, Poison, and Freeze all inflict damage over time, and can be combined for a solid 14 health lost per second. Pierce is useful for clearing out the hatchlings due to its piercing properties. Siphon will heal the player for 4 health, which helps if you are low on life.


The Seahorse Wand, crafted from 8 Ocean Bars, is a decent minion against the boss, dealing good damage with its projectiles.

The Living Wood Acorn, especially with the set bonus of the Living Wood armor, is a good supporting summon that does not occupy a minion slot while helping deal with the hatchlings or deal additional damage against the boss.


Shurikens are fairly common in Surface Chests and Pots, and can be additionally bought from the Merchant. Due to its fast throwing speed and piercing, these are capable of defeating the hatchlings while damaging the boss itself. Throwing Knives are similar to Shurikens, but trade piercing for damage; if you are willing to risk traversing the surface Corruption or Crimson at this point of the game, these knives can be updated to stronger Poisoned Knives. Star Anise are stronger variants of Shuriken, but are only available during Christmas; it is possible to craft a Holiday's Greeting, however, which will allow you to collect Star Anise.

When the boss is charging, it is particularly easy to throw a Grenade or Molotov Cocktail to deal high damage. Additionally, when the boss is preparing to charge, you can line the area in front with Sticky Grenades and get it to charge through them all. With Grenades, you should be careful to not blow yourself up from being in its explosion area.

Ocean Tomahawks pierce once and inflict Gouge, making it a possible weapon choice for the fight. If you use these, try to hit the boss on its downward arc to inflict additional damage.

If you encounter a Blood Moon, you can gather some Severed Hands, which are unaffected by gravity and are able to auto-fire, making them a strong option. They do not pierce any enemies, so you should save them for the boss itself.


Using radiant damage against The Grand Thunder Bird is not recommended; many of the available options lack the range to effectively combat the boss. Despite this, there are some options.

Leech Bolt is the best option for this fight. Though it requires the defeat of Patch Werk, it is the only weapon with enough range to reliably hit The Grand Thunder Bird as it hovers above the player, deals high damage, pierces once, and has life-stealing properties.

Alongside this, either the Life Quartz Claymore or the Heretic Breaker should be used. Like other swords, they benefit from being able to stun the boss and inflict immense amounts of damage for a short period. Between the two, the Life Quartz Claymore heals the player on hit while the Heretic Breaker deals more damage and can autoswing.

The Rotten Cod is excellent as a side weapon if you happen to fish it up in the Corruption. It has a longer range than other radiant weapons, deals adequate damage against the boss, and spawns healing orbs on hit, making it decent to use while waiting for your mana to recharge. Its Crimson counterpart, The Stalker, is not recommended however; it is dropped by the Brain of Cthulhu, a much more dangerous boss compared to The Grand Thunder Bird.

Finally, the short range of Pills make them largely useless for the fight, but it is possible to throw 2-3 Pills before the boss charges forward, adding free damage just before you stun it.


At this point of the game, the majority of your options are wind instruments. The Icy Piccolo is an excellent bard weapon for this fight, as it deals solid damage and inflicts Frostburn, allowing the player to continue damage the boss while their inspiration recharges. The Harmonica, should all three projectiles land, is stronger than the Icy Piccolo, but it should only be used when the boss is up close, such as before charging. The Flute, found within Surface Chests, is another option for this fight. Although its ability to home in on enemies is helpful, it is often too slow (both in terms of playing speed and velocity) to be too effective, and may even miss because it attempts to target a hatchling.

If you manage to purchase Dynasty Wood from the Traveling Merchant, the Dynasty Guzheng's wide spread and piercing properties makes it an ideal weapon against the boss. However, if you plan on using it, you should also collect some Inspiration Fragments to increase your maximum inspiration, as the Dynasty Guzheng uses a heavy amount of inspiration on use.

An alternative method to clear hatchlings is the Antlion Maraca. Though short-ranged, its high damage makes it a good sidearm when surrounded, and can be used against the boss itself if the opportunity presents itself. The Tambourine is only especially damaging with proper placement to hit on its rebound, but as it costs no inspiration to throw, it can be a decent weapon to chuck while recharging. Lastly, the Drum Mallet is not particularly useful, however as a broadsword, it is capable of stunning The Grand Thunder Bird mid-charge, allowing you to inflict large amounts of extra damage at no inspiration cost.

Pre-Hardmode Bosses The Grand Thunder Bird (Map icon).png The Grand Thunder Bird • The Queen Jellyfish (Map icon).png The Queen Jellyfish • The Buried Champion (Map icon).png The Buried Champion • The Star Scouter (Map icon).png The Star Scouter
Hardmode Bosses Borean Strider (Map icon).png Borean Strider • Aquaius, the Endless Tide (Map icon).pngOmnicide, the Life Defiler (Map icon).pngSlag Fury, the First Flame (Map icon).png The Primordials
Classes The Ring.png Class setups • Cleric Emblem.png Healer • Bard Emblem.png Bard
Crafting Arcane Armor Fabricator.png Crafting Quick Reference • Terrarium Defender.png Terrarium Defender