Main Walkthrough

The vast majority of enemies you fight in Super Mario RPG fit well into the Mario world. Koopas, Boos, Thwomps, Lakitus... even the addies unique to this game, like, say, Belome, have an unmistakably Mario air to them. There's one major exception to this, however, and he just happens to be Super Mario RPG's superboss.

This guide will help you locate and defeat Culex, an optional boss in Super Mario RPG. Culex is easily the strongest opponent you'll face in Super Mario RPG, so before we even track him down we're going to do some prep work.

Prepping for Culex

At a minimum you'll want to wait to fight Culex until you reach level 20 with your three chosen combatants. This is about the level where you can feasibly take on Smithy, the final boss, and Culex is harder to beat than Smithy. You can try to fight Culex at a lower level, but it won't go well. Anything above level 20 will make the battle easier, and going all the way up to level 30 is... overkill, but can't hurt your chances either.

You'll want to get the best equipment you can pick up for your party. If you're not interested in optional equipment this will mean the armor purchased from Croco's second shop in Bowser's Keep. His stuff is nothing special, but can be treated as the minimum. If you want to go above these items you should look into the following equipment:

Equipment aside, there are also several valuable, single-use items you can use on Culex to make the battle that much easier:

  • Rock Candies are one of your best weapons in this fight. When used they inflict 200 points of damage to every enemy, and that amount is boosted to 300 under the effects of Attack Up!, which Geno can achieve with Geno Boost. You can also get the Star Egg via Grate Guy's Casino, which has basically the same effect as a Rock Candy, though it hits for half the damage. Less useful.
  • Red Essences will make their user invincible for three turns. This will give you the opportunity to go on the offensive and not worry about healing.
  • Kerokero Colas are a great backup for Toadstool's healing abilities, and will fully restore everyone's FP to boot.
You don't need the stuff listed above to beat Culex, necessarily, but it all helps. Any other empty item slots should be relegated to Pick Me Ups, first of all, and then to other useful restorative items (Mushrooms, Syrups, Elixirs, etc.)

Finding Culex

Culex is hidden beyond a rather innocuous door in Monstro Town, and you'll need an item to get to him. You can obtain the key to his home as soon as you complete the events of Moleville, which is quite early in Super Mario RPG.

Once you've finished up in the Coal Mines and returned to Moleville the NPCs will offer some additional services. Among them is a Mole who will sell you Fireworks, and he lives in the western-most home in Moleville. Fireworks cost 500 coins apiece, so don't stop by with bare pockets. (If you keep buying Fireworks from this guy you'll change the ending of the game a bit, but that's neither here nor there.)

Outside this home is a lineup of crates, and standing behind them is a tiny Mole who is playing store. She will offer to trade you a Shiny Stone for the Fireworks you just bought. Make the trade and you'll have your key. Note that you can further trade the Shiny Stone for a Carbo Cookie and create a route to the Midas River rapids course, but... don't. Hold on to your Shiny Stone. You can come back to this girl and trade again if you want another Shiny Stone later, as well.

Head to Monstro Town. Next to the Item Shop is a locked door that will only open if you have a Shiny Stone in your inventory. Head inside and you'll find Culex, who will challenge Mario to a duel. Accept and the fight is on.



  • 4,096 (Culex)
  • 2,500 (Fire Crystal)
  • 1,800 (Water Crystal)
  • 3,200 (Earth Crystal)
  • 800 (Wind Crystal)


  • Ice (Fire Crystal)
  • Fire (Water Crystal)
  • Lightning (Earth Crystal)
  • Jump (Wind Crystal)
There he is. Ripped more or less directly from a Final Fantasy title, Culex is as un-Mario as enemies come. (He even has the boss theme song from Final Fantasy IV.) Powerful in his own right, Culex is accompanied by four colorful crystals, each of which adds to the pain you're about to endure. Culex and his crystals use the following attacks:
  • Culex himself employs powerful attack spells that either hit one target (Flame Stone, Dark Star) or multiple (Meteor Blast) for heavy damage. Culex can also use Shredder to remove status buffs from your entire party. Culex is also the only enemy that will use normal melee attacks.
  • The Fire Crystal uses a variety of Fire-elemental spells that will target one or more members of your party. No curveballs here.
  • The Water Crystal uses a variety of Ice-elemental spells which, again, target one or more characters. Also no curveballs, just pain.
  • The Earth Crystal uses a variety of non-elemental spells which target one or more characters. The most dangerous is likely Sand Storm, which doesn't do much damage but can inflict Fear status on the whole party.
  • The Wind Crystal uses a variety of Lightning-based spells. It can also use Petal Blast, which can turn everyone into Mushrooms, and Light Beam, which can put everyone to Sleep.
The battle against Culex isn't particularly complex, it's just brutal. Culex and allies get five turns per round, and they will use them to batter your party members with random spells. This can get quite overwhelming if your luck is bad and they happen to use moves to inflict status ailments. Your team can go from fine to demolished without you getting in a single attack.

If you're going for an 'easier' battle then you'll want to use items, and Rock Candies are your friends. Start the battle off by deploying your Red Essences to protect your team members, use Geno Boost to buff one or two members, and then start lobbing Rock Candies. They will inflict 300 points of damage per use to all of the crystals, as well as Culex, and quickly wipe out a few of your opponents. The Star Egg serves as a decent replacement once you're out of Rock Candies, and when you get down to, say, Culex and one remaining crystal, the fight isn't terribly difficult. Painful, yes, but manageable.

If you don't have any Rock Candies - or you're a glutton for misery - you'll need to take the long route of selectively targeting and taking out the enemies according to their threat level. Toadstool should be on healing duty while your other members attack, as you take too much damage each turn to ignore your HP. Go after the enemies in roughly this order:
  • First up is the Wind Crystal. In addition to its low HP, by far the lowest of the bunch, the Wind Crystal can Mushroomize and put your characters to Sleep. Both are terrible status ailments. Mario's Super Jump can wallop the Wind Crystal after a few well-timed uses.
  • Second should be the Water Crystal. At 1,800 HP it can't withstand a ton of abuse, and you want to get rid of one of the other crystals so you're not getting hit too many times per round. Mario's Super Flame is good at wiping out the Water Crystal.
  • Third should be the Earth Crystal. It has the second-most HP, true, but Fear can demolish your party if you get caught trembling. Mallow's Shocker move is great against the Earth Crystal, though normal attacks also work reasonably well.
  • Fourth is the Fire Crystal. It is arguably the blandest of the crystals in terms of its moves, inflicting only damage, and shouldn't pose a major risk with the other three crystals gone. Ice attacks are difficult to come by, aside from Mallow's FP-heavy Snowy move, so stick with a melee pounding.
  • And, last, Culex. He is dangerous for the entirety of the fight, but he has too much HP to try and take down at any point but last. Once Culex is alone you shouldn't have any trouble slogging your way through the remainder of the battle. 
The need for consistent healing cannot be understated. If at any point you lose Toadstool and can't get her back, you are probably done for. Always have a big stock of Pick Me Ups available, at a minimum, as Toadstool needs to heal almost every round. On the off chance that Toadstool's turn comes up and she doesn't need to heal, you should probably just have her defend. Hedge your bets.

(Fun note: This is one of few fights in the game where it is likely that the boss will run out of FP before the end. If you see that Culex is out of FP then you've pretty much won, aside from his physical attacks. He'll waste maaaaany turns trying to uselessly cast spells.)

Defeat Culex and you'll receive the Quartz Charm, which boosts the wearer's offenses and defenses by 50% and protects against instant death attacks. (Though if you managed to beat Culex, you... hardly need it.) Culex's realm - and door - disappear after he's defeated, so, alas, you can't fight him again. Still, well done!

Main Walkthrough