So I've been toying with this idea for a while now and decided to finally go for it.

Boos. What are they?
Think about it: they're ghosts, but barring the few shows, games, films, books, or plays that state otherwise for their own lore's purposes specifically, it's a well known "fact" if you will that ghosts are the spirit of a deceased being, still roaming the earth instead of resting as they should. So then seeing as how (to my knowledge) it has never been explicitly stated that Boos were born ghosts, it stands to reason that in the world of the various Mario series', the little ghosties were indeed once alive. So what were they in life? And why do they want so badly to kill Mario yet when face to face with him act as though they are, well, terrified of him even though he is literally powerless to harm them? Surely they know he can't hurt them, so why are they apparently so afraid of him? Did they have a run in with him in their previous life, you know, when they were actually alive? And if so, what did he do that instilled such a fear inside of them?


You may or may not have noticed FaithFighter's new character bio for Goombas, but go give it a read, as it ties pretty nicely into this theory despite the theory preceding it by a good bit.
Think about it: when was the last time (barring Mario RPGs and such. This is strictly Super Mario game lore) that you were playing a Super Mario game and a Goomba outright attacked you? Koopas? No? Exactly: they are apparently harmless creatures that simply walk (or in some games, dance), minding their own business. In fact if left alone most of them will just walk off of a cliff, while some turn back and head back to where they came from when they reach a dead end. Still, Mario kills them in order to protect himself (I guess?), as it seems that when his unprotected skin touches them he has the unfortunate reaction of death. They killed him! Or did they? Quickly, replay every death to a Goomba or Koopas that you can think of. Ever see them attack him? Bite him? Anything? No, they merely walk into him. I do this all the time in real life, but thankfully no one has ever pulled a gun and shot me for it (or worse, jumped on my head until I died...or kicked me over a cliff. Or set me on fire.. Yay Mario).

Still for arguments sake, we'll say that Mario doesn't kill them for the sake of doing so, but reckons that jumping OVER them wouldn't suffice and instead death for them is necessary. So he does what he must. Can't blame the man if he feels he has no choice, right? He simply needs to save the kidnapped princess after all! But that does nothing to make it any better for the poor helpless creatures he massacres on his way to save her. No, they are still as dead as dead gets, and with a death so bad as being stomped to death must be, I imagine those last few moments must be pretty...well, horrifying. Frightening. Scary.

See where this is going yet?


So I ask you: is it possible that Boos are simply the spirits of these creatures seeking revenge for what Mario did to them during their lives? This would certainly explain their fear of him, as just one glance into those eyes reminds them of what happened. That horrifying death. That this man is one to be feared.

And even if they somehow are sinister and diabolical creatures with an evil genius plan to kill Mario and conquer the Mushroom kingdom by walking mindlessly off of cliffs, this could still be the case of the Boos and their fear. This man ended their lives in a doubtless painful and horrible way. He may be the hero and maybe they were evil for walking, but even then it would be reasonable to be afraid of the man that brought this swift and painful justice upon them.
Finally, it bears mentioning that it wasn't until Super Mario Bros. 3 that Boos even began to appear. Before Mario started fighting and killing these creatures - justly or not - the Boos seemed to have not even existed. Coincidence? Maybe. Maybe not.


So how about it? Is it possible? Are Boos really the spirits of creatures Mario has killed at some point? Is this why they fear him? Or am I off my rocker? Maybe it's all the above.

Eirinn : Way to give MatPat a run for his money!

I think that the theory is very plausible. I think that this could also explain why King boo is always so mad at mario. Of all the innocent creatures, King boo was once the greatest. And he sits by watching helpless as he sees all his kin being slaughtered. This also shines a contrast against Luigi, who in his game, is putting those spirits to rest (sorta). at least he's actually got stuff attacking him! Honestly, though, I can't figure what creature he would have been.

Also, boos aren't the only ghosts in the super mario series. There's also the dry bones, as well as the ghosts that actually look more ghostly. And also...what of the shy guys, remember these guys did appear in Luigi's mansion, though different. It's almost as though they really are ghosts of some kind, but they hide under their disguises. Perhaps each ghostly figure is the spirit version of different creatures, with the goombas as boos, koopa troopas as dry bones, the hammer, fire, ice bros as the more ghostly ghosts. And I just remembered, shy guys appeared in the yoshi games, which tend to be at the beginning of the mario timeline. Scratch them being a ghost of mario's doing.

At any rate, with all the unusual theories that are starting to pop up about mario. It's difficult to know what we are supposed to believe. What doesn't help is that nintendo hardly tells us anything about this series. But yes, I think that this would explain a couple of things.

FaithFighter : Thanks! And yeah I meant to mention the dry bones as they are clearly an "undead" form of the koopas which would seem to imply that they had been alive at one point.

Also interesting is that the Boos, unlike other ghosts in Luigi's Mansion, ran from you instead of attacking you directly, or that's how I remember it anyway. But even then they had provoked Luigi and kidnapped his brother so it makes sense why he would fight them.

Thanks for the additional input!

EDIT: Why so many double posts? Dumb connection speeds. -__-

Eirinn : The boos actually tend to be a very tricky enemy. You have to seek out all of them, after luigi let them all escape... They play a lot of hide and go seek, and basically they try to jumpscare luigi. I'll never forget that boo trapdoor scene. After watching it, I couldn't help but sing

"Who let the boos out? Luigi, Luigi! Who let the boos out? luigi! Luigi!" Ah such fun that game is!

Also, I happened to think of something else, what about the ground boos? If boos came from goombas, did the ground boos come from paragoombas?