I've heard this rumor tons of times, trying to find out the truth. (I'm not an Earthbound hater, I love the series.)

TG: giygas is not actually a fetus
TG: giygas was originally known as giegue before he was corrupted and became the embodiment of evil
TG: many people say that giygas is a fetus simply because of the figure one of his stages makes
TG: that of one similar to an unborn child, obviously
TG: most people say this because of having heard of the story of shigesato itoi walking into the wrong screening of a movie
TG: and at this screening he saw a movie called "the dismembered beauty" or somethin of the sort
TG: he supposedly walked into a rape scene, but no such scene is present in the movie
TG: said scene also supposedly inspired giygas' dialogue
TG: people also believe giygas to be a fetus due to the odd intestine like passageway before reachin giygas
TG: and also the overall appearance of the cave of the past
TG: in reality giygas is simply the corrupted form of giegue whom was an alien of a species knowin psi
TG: if youd like to learn more about giegue i suggest playin mother 1
TG: hope this helped

tipsyGnostalgic : Why did you keep putting TG: before every sentence?

No lol Giygas is an alien that somewhat looks like a skinny mewtwo. The fetus seen in the battle resembles a human fetus which Giygas is clearly not so it wouldn't make sense to be him. Say the fetus was intentional though which could mean the battle itself is symbolic of that sort of idea considering Giygas is based off how he felt about a traumatic rape scene (or at least he thought it was) he saw as a child. In Mother 1 you battle Giygas looking like his normal self which is clearly alien basically disproving that he is a fetus, let alone a human one

Edit: When I said he I'm referring to Shigesato Itoi the creator of the Mother series

rcarter2 : tis the initials of my username
if thats not alright i can always stop
just a thing i do
to my knowledge it doesnt count as a word so i dont think theres really any harm in it
but like i said
if thats not somethin i should do
go ahead and tell me
i have no problem stoppin

tipsyGnostalgic : It does add to your word count. The only time something like that doesn't count as words is if it is an actual user summon. It isn't a huge deal, but would be best to go ahead and stop because I can see some users turning it into a users (particularly during posting competition months).

Nope. Giygas is more like the Ovary... or something like that. I don't remember what it was, but Giygas isn't a fetus.

lern 2 anatomy

It looks to be a fetus in the womb, which is very creepy, which is why I never will beat Earthbound because I do not want to fight it myself.