Issue Description:

While having both Chickens and Mo Creatures installed at the same time, all of the chickens that spawn in the overworld or nether don't, even though the rooster can spawn. Would this be a problem with Mo Creatures or Chickens? How would I get the chickens to spawn?

TBH I couldn't tell ya. Chickens get spawn via normal vanilla forge spawning. So I would say it has to do with Mo Creatures. They may be canceling out anything that extends of chickens to change the spawn.