Issue with Chicken Defense?

Hey. So... I have an issue with the Chicken Defense gamemode. On the Wiki article, it states that eventually, the Hive will send out the chicken Queen, but I never get that far. What I mean is, the Hive gets angered, and sends out a White Dragon, and then I win as soon as I kill it. So, am I supposed to ignore the creature? Is this a bug? How do I get the Queen to spawn?

If you play on easy difficulty there wont be a chicken queen, instead, the white dragon appears.
Try normal difficulty or higher.