Chillmaw has risen as one of the most popular Frost Wyrm in Northrend recently. It has caused Threat From Above to the argent tournament and nearby areas. Hence, Crok Scourgebane has requested many champions to destroy it before it has chance to use its Claw of the Frost Wyrm against us.
Below is the excerpt of Frost Wyrm from Battle.net
In ages past, the ancient Dragons who were near death flew to the land of Northrend to die. To this day there are entire Dragon graveyards that are littered with massive petrified bones and skulls. When Ner'zhul the Lich King took control of Northrend, he used his powerful magics to raise the ancient Dragon skeletons from the dead. Now the skeletal Dragons radiate cold power and think of nothing other than serving their dark master. Frost Wyrms have a cold-based breath weapon that can do shattering damage to enemies both on the ground and in the air.