5. Gooper Blooper

From Super Mario Sunshine

The Gooper Blooper in Super Mario Sunshine, an already tough game considered by most Mario fans, might by far not be the most difficult boss in the history of Nintendo; but we can all agree on how messed up this specific boss is. Imagine you’re just chilling and enjoying the sun in your beautiful home island; you’ve heard some stuff about a mustached guy messing up with the place and you suddenly see him carrying a water-filled gun who starts to rip your body apart while you just try to defend yourself as you have nothing but only been a victim of the acts committed in the island. You die. You are murdered. By Mario.

4. Ruined Dragon

From Super Mario Odyssey 

Nintendo has been mostly known for their quality games rather than the power their consoles handle, which is often translated into the visuals of their first-party productions; but what the guys from the Super Mario Odyssey did with the tools they had on their hands was honestly amazing and we can mainly see it in the Ruined Kingdom’s atmosphere and only boss: the Ruined Dragon. It isn’t nightmare-inducing or the most difficult boss in the series, but it is 100% one of the most memorable thanks to its gameplay and incredible visual style.

3. Antasma

From Mario & Luigi: Dream Team

Mario & Luigi: Dream Team’s Antasma's biggest strength doesn’t come from its creepy appearance either from the AMAZING OST Yoko Shimomura composed for this specific three-stage fight, but rather from the fact that it has been the boss to be the most afraid to fight Mario in the history of the Super Mario franchise with several obstacles to go through before the final showdown. Mario & Luigi’s RPG bosses tend to be the most creative inside of the Nintendo headquarters, which takes us to the next two spots.

2. Shadow Queen

From Paper Mario: The Thousand-Year Door

The final boss from the RPG Mario by excellence had to be here; by creating an incredibly creepy atmosphere and building up a story like no other in the history of Nintendo, the Shadow Queen takes the second spot for not only having a terrific and terrifying look and song but also for being one of the most original and creative Super Mario Bosses to date.

1. Super Dimentio

From Super Paper Mario

I could about hours about how Super Paper Mario is one of the best story-driven games to ever be released, and lots of Mario RPG fans could answer back to me arguing on how unfair it is that the Shadow Queen didn’t take this spot, but give a second. I consider Super Paper Mario to be the best one out of the Paper Mario series; and while it heavily relies on a gimmicky Wii feature and has more platform moments than RPG ones, you just have to pay close attention to the development of the story we are told in Super Paper Mario, one of the saddest and most beautiful love stories to come out in the entertainment industry in the last couple of decades.