Culex

"I am matter... I am antimatter... I can see your past... I can see your future... I consume time... And I will consume you!"

- Culex

Culex is an optional hidden boss that appeared in Super Mario RPG: Legend of the Seven Stars. He is a Dark Knight from the alternate dimension of Vanda. Culex could be considered a crossover character from the Final Fantasy series, although he has never appeared in a Final Fantasy game. Nevertheless, the Dark Knight was designed as an allusion to the Final Fantasy series, as both Super Mario RPG and Final Fantasy were developed by Square-Enix (at the time of the game's release, Squaresoft). Culex resides in Monstro Town, waiting for the world's "strongest knight."

''Super Mario RPG: Legend of the Seven Stars
Before or during the events of the game, Culex crossed over from his dimension of Vanda to Mario's dimension, ending up on the Mushroom World, Mario's home planet. The Dark Knight was sent to Mario's world to fight on behalf of the Dark Mage, possibly with the intention of conquering the world. However, Culex discovered that Mario's dimension was actually uninhabitable by himself and others of his kind. As such, Culex would be forced to return to Vanda without completing the Dark Mage's assignment, as the Dark Knight could not survive in the Mushroom World's environment. Before he would leave for his home dimension though, Culex wished to the battle the Mushroom World's "strongest knight." The Dark Knight eventually came to reside in a cross-dimensional region found behind a sealed door in Monstro Town, a village of reformed monsters located in Land's End. Despite waiting in a dimensional rift, Culex's next-door neighbors could still hear the Dark Knight talking to himself through the walls. According to one of his neighbors, a Piranha Plant, Culex was "always mumbling about Crystal-this and an Evil-that."

The seal to Culex's dimensional vortex was eventually broken by Mario, the champion of the Mushroom Kingdom. Mario and his party discovered the mysterious sealed door during their travels to Monstro Town. The Piranha Plant neighbor of Culex actually provided a clue to opening the sealed door, reporting to Mario about Culex's obsession with Crystals, and then hypothesizing: "Isn't a 'Crystal' some kind of a shiny rock...or something? I know I've seen those somewhere!" This "shiny rock" was actually a Shiny Stone, a small crystal that could be acquired in Moleville. To retrieve a Shiny Stone, Mario first had to buy the Fireworks from a male mole in Moleville for five hundred coins, then trade the Fireworks for a Shiny Stone from a young mole girl in the same town.

Upon returning to Monstro Town with a Shiny Stone in his possession, Mario attempted to open the sealed door, causing the small crystal to begin reacting, eventually dispelling the magical seal. The door could now be opened, allowing Mario and Company to access Culex in his dimensional vortex. After Mario entered the dimensional rift, Culex would greet the visitors and explain his back-story. The Dark Knight then challenged Mario, who Culex viewed to have the potential to be the world's "strongest knight," to a battle before he had to leave for his home dimension of Vanda. The plumber could either accept or refuse Culex's offer. If Mario refused, Culex would say "You are wise to hesitate. Without any weapon or armor, you have no chance." Mario would then be forced to leave the dimensional rift, but could return as he desired at a later time. If Mario accepted the challenge, Culex would declare "En garde!" and the battle would begin.

In battle, Culex was aided by four seemingly sentient crystals – the Earth Crystal, the Fire Crystal, the Water Crystal, and the Wind Crystal. Each crystal had command over potent magic attacks aligned with their elemental power (for example, the Earth Crystal knew the special attack Boulder, which could damage Mario and both his allies in one strike). Culex himself was a powerful fighter, who had over 4,000 HP, the most of any character in the game besides the final form of the final boss Smithy. Furthermore, the entire group of beings had over 12,000 HP, much higher than the final form of Smithy. The Dark Knight was also a master of advanced magics such as Shredder, Meteor Blast, Flame Stone, and Dark Star. All four Crystals could be defeated independently before targeting Culex, but if Culex was defeated, any remaining Crystals would shatter one by one on their next turn.

If Mario prove victorious against Culex and his Four Crystals, the Dark Knight would congratulate the world's "strongest knight." Culex was then able to return to Vanda satisfied, but before he departed, he told Mario: "Thank you, brave knight. I will treasure this memento of my journey here.  Perhaps in another time, another game, we may have been enemies... Let us part as comrades in arms." The Dark Knight then rewarded Mario with the Quartz Charm, a special Accessory that could boost attack and defense by 50% and also prevent instant death. Culex requested the plumber to "[t]reasure it as a keepsake of our fight." Culex then left for Vanda, uttering the words "Farewell, champion knight!" Mario and company were transported back to Monstro Town, and the door to Culex's dimensional rift disappeared, leaving a solid rock wall in its place.

Culex was later mentioned by Dr. Topper when he was quizzing Mario at Bowser's Keep. He asked Mario what Jinx, Goomba, and Culex all have in common. The correct answer was: "They all live in Monstro Town."

Allusions to Final Fantasy
As mentioned above, Culex stands out in the game Super Mario RPG for being an allusion to the conventions of the Final Fantasy series. Culex is described as being a Dark Knight, a common class of character from the Final Fantasy series. Furthermore, Culex's master, the Dark Mage, may be a reference to the Black Mage, another common class found throughout the series. Also, Culex notably has two different sprites in the game, one for the overworld and a much larger one for battle, just like bosses in the Final Fantasy series. Super Mario RPG enemies, on the other hand, have the same sprite for both the overworld and for battles. Additionally, Culex himself somewhat resembles the final form of Kefka, the final boss of Final Fantasy VI. Indeed, in the style of early Final Fantasy games, all enemies and bosses are rendered as static pieces of two-dimensional character artwork, lacking any kind of animation. Similarly, in battle Culex is rendered as a two-dimensional image that does not change when attacking or being attacked, unlike the three-dimensional models of all other enemies in Super Mario RPG, which can go through complex animations when attacking, being attacked, and even walking in place. The Four Crystals used by Culex in battle are also important reoccurring artifacts from the Final Fantasy series, appearing in many games in the series with different functions in each. All four elemental Crystals featured in the battle are from the original Final Fantasy for the Nintendo Entertainment System. Moreover, the three music tracks played when around Culex are remixes of three music tracks from the Final Fantasy series. His Battle Music is a remix of the Battle Music from Final Fantasy IV, the music that plays when Mario defeats Culex is a remix of the Victory Music present throughout the Final Fantasy series, and the Conversation with Culex is a remix of Final Fantasy's main theme. Lastly, Culex breaks the fourth wall when telling Mario: "Perhaps in another time, another game, we may have been mortal enemies..." The Dark Knight is of course referring to his origin from the Final Fantasy series, versus Mario's place in the Mario series.

Trivia

 * Culex shares his name with a genus of mosquito.
 * Culex plays the very same role that The Master, Bonetail, and Shadoo played in the Paper Mario series, as they are all optional bosses that are (supposedly) stronger than their games' respective final bosses.