[Randomizer]

In the first game, the Moos were followers of Ghadius and Joka relay orders to them. Their purpose there was to stop Klonoa from foiling their master's grand plan in any means necessary.

Who is their leader now in the second game? Were they under the King of Sorrow's command or were they hired by Leorina to work for her as minions?

Alright, let's do this.    

[mnstrmthd]

Honestly I never thought they had a leader? At least in LV?
The moos just kinda loaf around minding their own business most of the time. The other enemies, while more aggressive, are still just doing their own thing for the most part. They're basically just part of the wildlife as far as I'm concerned.

[Sable-Xeno]

I'm gonna go with Mnstrmthd on this one. They're kinda comparable to Waddle Dees: they serve under someone in their original appearance, but in several subsequent games, they're more or less just peaceful little guys that just happen to be in the wrong place at the wrong time. Either that, OR Joka just had a lot of Moos under his control, but not ALL of them. Just the ones that were willing, I guess.

[AlphaRed9X]

I assumed the Moos and monsters were running amok because of the Chaos that Baguji mentioned. I think that since the fifth kingdom was isolated from the rest of the world, it may have caused the monsters to become hostile and run about as a result of the world being out of balance.