Valerdan Pack

Valerdan Pack's strength and toughness is 5+X/5+X where X is the amount of werewolves you control.
When another werewolf you control dies, put an enrage counter on Valerdan Pack.
When Valerdan Pack has 10 enrage counters on it, destroy all non-basic land, non-werewolf permanents. They can't be regenerated.