Tackling both monsters head-on would have netted you both rewards.>>15860586You ultimately decide not to intervene, it's not your fight anymore. Maybe it was, but then the toxic behemoth thought you were taking too long to win, or you handled it in the suckiest way possible, and he decided to just take matters into his own gross hands. Besides, you don't have anything of size to actually FIGHT either of those two, this is a saving grace for you.
The two beasts immediately don't get along with each other, and it's quite easy to see why. They're practically night and day as far as design goes and frankly they each think the other sucks major badonkaballs.
"OOOOOONIX!"
"SCREEEEEEEEEEEEE!"
"What do you think they're saying to each other?"
"I don't know, Calem. I speak many things, but I don't speak monster."
It's like watching something out of a Godzilla movie, just with the titular character replaced with a crystallic Onix who's supposedly been causing a ruckus in this cave for the longest, and a poisonous goliath who lacks a head but makes up for it in raw power.
After enough stalling, they engage in a brawl that takes the cavern by storm, Ferroseeds start pouring in from everywhere, some actually stick onto the two fighters, but all the Irons Barbs in the world wouldn't be enough to deter them from killing each other.