The Final Fantasy series is home to some truly unusual bosses. Though it depends on the series entry, most titles tend to feature an array of bizarre foes. What makes these bosses strange usually comes down to their design, the arena they are fought in, and the way they fight the protagonist.
As a JRPG series, it makes sense for Final Fantasy boss battles to get a bit strange from time to time. Being strange doesn't always make it a bad thing, however, as some battles tend to use these strange aspects to stand out from other, more ordinary bosses.
5 Biran & Yenke Ronso - Final Fantasy 10
Upon reaching Mt. Gagazet in Final Fantasy 10, Kimahri will be thrust into a battle against two Ronsos named Biran and Yenke, aggressive bully-like characters who harbor a grudge against Kimahri for abandoning their homeland. Instead of facing the two Ronsos with the usual three party members, players will need to rely on Kimahri to dish out the damage.
The battle against Biran and Yenke is strange for several reasons. For one, it forces players to make use of a character they likely haven't been using too much. What's interesting about this is that the battle will vary in difficulty depending on how powerful Kimahri is. Another strange aspect of the battle can be seen when Biran and Yenke bulldoze their way past Kimahri. This will often restrict players from using AOE attacks, as one Ronso will often be out of range. The battle against Biran and Yenke is designed exceptionally well, but it's hard to deny how strange it can be.
4 Sorceress Adel - Final Fantasy 8
Facing inconsequential enemies in the Final Fantasy series usually doesn't have repercussions, but it can be difficult for players to face party members they have come to know and love. For the battle against the Sorceress Adel, Squall and his companions not only need to face a terrifying boss, but they will also be directing their attacks at Rinoa.
To survive the battle, players must ensure they avoid attacking Rinoa, but it's easier said than done. Some attacks deal damage to multiple enemies, so certain moves should be avoided at all costs. Sorceress Adel will drain Rinoa's health regularly throughout the battle, forcing players to heal her whenever they get the chance. If Rinoa's health is completely drained, the battle will be lost, so players need to try their best to avoid inflicting harm on her while also protecting her from Sorceress Adel.
3 Ultros - Final Fantasy 6
Ultros is a recurring boss in the Final Fantasy series, whose main purpose often tends to revolve around comic relief. In Final Fantasy 6, Terra and her companions must defeat this purple octopus four times before he stops interrupting their journey, but it's sometimes easier said than done.
While most battles against Ultros tend to be quite difficult, the battle that takes place inside the Cave is arguably the most notable. Upon depleting enough of Ultros' health, Relm will join the battle. Instead of fighting her, however, Ultros opts to insult her, which causes the rest of the party to jump to defend her. They scold Ultros for his behavior and demand that he apologizes for his words. He eventually concedes, apologizes to Relm, and even asks her to paint his portrait. Unfortunately for Ultros, Relm's painting abilities can be used to mimic the attacks of her enemies, a skill that proves to be Ultros' downfall.
2 Famed Mimic Gogo - Final Fantasy 5
Bartz and his companions will encounter the Famed Mimic Gogo boss guarding a Crystal shard in the depths of the Walse Tower. Upon interacting with the shard, a mysterious voice will forbid him from taking it, and if Bartz refuses the voice's commands, he will be launched into a boss battle.
The boss battle against the Famed Mimic Gogo is unlike any other battle in Final Fantasy 5. Before the player can begin their assault, Gogo will warn them of what's in store. Whenever the party attacks Gogo, the Famed Mimic will retaliate with a similar attack of his own. Though it makes sense in hindsight, the only way to beat the Famed Mimic Gogo is to wait for the timer to count down. After enough time has passed, Gogo will praise each party member for their excellent mimicry skills before offering them his power. What makes the battle against this boss so strange is that the player doesn't even need to lift a finger to win it.
1 Mandragoras - Final Fantasy 12
While traveling through the Tchita Uplands, Vaan and his companions will encounter a young boy who, when approached, will ask for help. The boy's father has been searching all over Ivalice for bounty hunters capable of defeating the great evil that lurks inside the Sochen Cave Palace, and when his son meets Vaan, he believes he possesses the power needed to vanquish it. Once the hunt has been accepted, the player can continue moving forward until they are greeted by the Mandragoras.
Upon reaching the inner sanctum of the Sochen Cave Palace, Vaan and his companions will be forced into a battle against the Mandragoras, five adorable creatures whose designs are reminiscent of vegetables. Though they may not look it, they can quickly devastate the party if the player isn't fast enough. Unlike most bosses in Final Fantasy 12, the Mandragoras spend most of their time fleeing from the party and only attacking when they believe it is safe. Sadly, these five bosses tend to heal themselves when they are out of range, a tactic that makes defeating them quite difficult. What makes this battle so strange is how the Mandragoras were designed; they don't look nearly as threatening as their powers would suggest.