Axros, Stone Warden

Axros, Stone Warden enters the battlefield tapped.
When Axros, Stone Warden enters the battlefield it gets +0/+2 for each Mountain on the battlefield.
When Axros, Stone Warden enters the battlefield it gets +2/+0 for each Forest on the battlefield.
When Axros, Stone Warden is destroyed you may sacrifice a mountain and a forest to return Axros, Stone Warden to the battlefield tapped.