Paper Mario: The Thousand-Year Door is one of the best games of the GameCube era, not only for its amazing gameplay but its memorable interactions with bosses. There were many difficult bosses in this game, but Mario interacted more with them, rather than just reaching the end of a set of levels and fighting the random enemy that looms there.
The bosses had meaning and impact, making them relevant even in later titles where they may or may not have been referenced. These are the 10 hardest bosses, as well as advice on how to make fighting them a lot easier.
10 Macho Grubba
Fought in the Glitz Pit as the final fight in the chapter, Macho Grubba has the ability to raise his stats, including attack, defense, or even evasion. He can also attack with a running punch or a stomp, which are both pretty easy to defend against because of how telegraphed they are. He can also increase his turn count, giving him a chance to attack twice in a row, which will allow him in later turns to buff himself before attacking.
The best partners to use against him are Koops and Flurrie, since his defense buffs will make Mini-Yoshi and Goombella do little damage. Power Smash and Power Jump are also good badges to have equipped on Mario to do extra damage.
9 Cortez
This boss has three forms, with his final one being the most difficult. In his first form, he can hit Mario multiple times with his swords. In the second, he gets a bit weaker, but can still hit Mario multiple times for some decent damage.
But in his final form, Cortez's weapons float in the air as he attacks, giving him five attacks, technically. Bobbery and Vivian are the best partners to use in this fight, having attacks that hit multiple enemies. Vivian especially shines here because her Fiery Jinx inflicts burn onto everyone, making them take damage over time.
8 Doopliss
This ghost is stronger than the Boos in his mansion when you fight him. After Vivian chooses to help Mario, who has had his body stolen, the fight becomes interesting. Your best bet is to fight Doopliss himself. Don’t worry about your partners. Goombella is very easy to counter. Doopliss is also using Mario’s moves, so timing is very similar, with the hardest thing being the hammer that you’ll have to counter.
Vivian can inflict Doopliss with a burn, so he will constantly take damage over time. In later fights, Doopliss can transform into any of Paper Mario's partners, requiring you to remember how each of their attacks works to successfully defend yourself.
7 Rawk Hawk
Rawk Hawk, along with having one of, if not the best battle theme in the game, is also the second to last boss in the Glitz Pit. He will use moves like a wrestler, such as flipping into the air or sliding to kick the frontmost party member. His flip especially can be a little tricky because it comes out fast. Rawk Hawk also uses his dive move, one of his trademarks, where he jumps into the air and dives at someone, dealing massive damage. However, this move is slow enough to block.
After sustaining some damage, Rawk Hawk will bring down the rafters and shake them, causing objects to fall on Mario and his partner’s head. You’ll have to use the Quake Hammer or Hammer Throw to knock him off unless you rely solely on jumping. The Mini-Yoshi is the best partner for this, because of his high damaging default move.
6 Shadow Sirens
The Shadow Sirens fight changes from the first time you meet them. With Vivian being a member of the party before joining Paper Mario, the Sirens had to replace their lost member with Doopliss. In the Palace of Shadow, Beldam fights by buffing her team or debuffing Mario’s with her spells. She doesn’t have as much health as Marilyn, the brawn of the group.
Marilyn will buff herself and can use lightning that will hurt both Mario and his partner, as well as Beldam using ice that can freeze them. Vivian, while fighting with them in the first fight, was able to inflict burn onto Mario or his partner with a strong punch. Multi-targets moves are the best to deal with them, so Bobbery and Koops are prime partners to use.
5 Smorg
You fight this creature on top of the Excess Express, and it uses its tentacles to attack. They are fairly easy to defend against and can be destroyed to limit their attacking power. While fighting, Smorg can also summon a pinching tentacle, capable of attacking both Mario and his partner for MASSIVE damage. He’ll deal 10 HP worth of damage if he connects with it, unblocked.
Using Power Lift throughout this fight will make things a lot easier for you, as well as using Vivian to destroy tentacles at the same time. When the pinching tentacle comes out, you’ll need to focus fire on it instead of ignoring it. A mix of the new Spring Jump ability and Power Lift should make quick work of it.
4 Bowser & Kammy Koopa
The Koopa King is fought twice in the game, once in the Glitz Pit and again in the Palace of Shadow, with the latter being the harder fight specifically because of Kammy Koopa. He will have standard attacks, such as using fire and biting Mario, which can poison him, especially if he does not guard. Bowser also has a stomp move that can take away Mario’s commands, as well as do good damage.
Kammy Koopa makes it harder because she works similar to Beldam, buffing Bowser and debuffing Mario and his allies. She can also heal him, making her a primary target at the beginning. You’ll need to focus on her, or else Bowser will do massive damage to the team. Also, since Bowser is a spiked enemy in this game, jumping on him is ineffective, requiring the use of the hammer. Using Vivian or Bobbery to hit both Bowser and Kammy at the same time is best.
3 Sir Grodus
Grodus, leader of the X-Nauts is the third to last fight in the game. He attacks with blasts that can freeze you or your partner, as well as lightning to zap you. He can also burn the team with fire. Sir Grodus does a ton of damage as well, so you’ll have to have your blocking skills perfected. Plus, the boss has a barrier that consists of four weak points that will protect him.
The barrier will only form if four of them are present, and Sir Grodus will bring more nodes every turn until he has four back, summoning the barrier. Multibounce and Supernova are two moves that Mario can use to quickly take down the nodes, and Multibonk and Fiery Jinx can help from Goombella and Vivian.
2 Shadow Queen
The Shadow Queen is the final boss of the game and is one of the strongest enemies. Initially, she will be invulnerable as she has possessed Peach. But after using the Crystal Stars to gain energy, the barrier blocking her damage will be destroyed, allowing Paper Mario to deal damage.
The Shadow Queen has many moves that involve her hand smacking either Mario or his partner. She can inflict status effects with mist and use a powerful wave of energy after she increases her attack power. Vivian is almost essential for this battle, as she is able to harm the Shadow Queen's hands and protect Mario from her ultimate attack with Veil. Power Bounce is very good at dealing with her consistent damage.
1 Bonetail
Bonetail is at the bottom of the Pit of 100 Trials and is the hardest boss in the game. Similar to the Shadow Queen, Bonetail can inflict many status effects, depending on the color of breath. Guarding will make sure you don’t take too much damage, but having items that heal status conditions would be good too.
Also, Bonetail can heal when he is on low health, so you’ll have to outlast him with a partner that has enough HP. He also has a stronger, charged attack that, similar to the Shadow Queen, requires Vivian to Veil to dodge, unless you want to take massive damage.