After large amounts of Pikmin 3, I went back to playing Pikmin 2 for a while. This time through, I thought about something I never had before. I fought a the Raging Long Legs, and I noticed how, since I had completed the Hole of Heroes previously, it released a swarm of Mitites. Amidst the shrieking and flailing of the terrified Pikmin, an idea formed in my mind. Using the wonderful, splendiferously helpful Piklopidea, and my prior knowledge on entomology, I have come to the conclusion that this massive creature is in fact female.
Learning from the Piklopidea, Mitites lay their eggs in the eggs of a hosting female species. This is known as sexual parasitism (gross, right?) and is used frequently be insects such as wasps in real life. Since the Raging Long Legs drops Mitites, in makes sense that they would be located in the developing eggs of the creature. This means it is in fact a soon-to-be mother, and thus female.
Also, Olimar states that little is known about the internal workings of the creature, so there is that extra room for speculation.
When looking at the Raging Long Legs, one might say "how does it support its abdomen?" That is indeed a good question; the thing is stupidly large for its thin legs, and even looks a bit too big for its feet. The answer is that it doesn't have to, at least not all the time. Simliar to how a pregnant woman becomes shall we say... rounder(?) when pregnant, insects abdomens increase drastically in size when they are soon to lay eggs. This is especially visible in many moth and butterfly species. So this means that perhaps Raging Longs Legs on a normal day would be much smaller, but still significantly larger than the Beady Long Legs.
Also, when almost any animal is pregnant, it becomes extremely ornery, protective, and territorial. This explains the creature's raging behavior.
So there you have it, the beast you kill in the Hole of Heroes is just trying to become a mother, but is being plagued by both you and parasites, and it explodes right there and then. You monster.
That's what you get when you apply arthropod anatomy to a video game. The scary spider monster, though it may appear masculine, is just as female as your sister-in-law. This means that a male Raging Long Legs must exist as well. Back to PNF-404! Further research is needed! For science!
Any holes you see in this theory? If not, then thanks for reading, and I'll see you back at PNF-404.