I guess this is a plot hole (amongst several others) in Alien 3, as it has NEVER been clarified as to how the Ox Xenomorph is different from other xenomorphs we have seen thus far, apart from the fact that it walks on four legs and with high speed, which aren't really radically different.
The ox (or dog, depending on what version of the movie you watch) was face-hugged by a queen face-hugger, so wouldn't that mean that the xenomorph that burst out of it is a queen?
Remember, both Ripley and the Ox were impregnated by the SAME facehugger. Yet, the Ox Alien is simply quadrupedal and fast, and not enormous and dominant as the queen we see in Aliens. And I assume the version we see in the movie is the alien as its most mature. Even at birth, we see that it's way bigger than a regular chest-burster, implying that it's a queen. Yet we never see it go that direction for some reason.