After transforming or taking over the host, they stand somewhere around 7–8 feet tall, are bipedal, have significantly improved musculature (probably regardless of the host's build or stature), long forelimbs and hind limbs (although the forelimbs appear marginally larger). Unlike their mythical counterparts they have no weakness to silver and are extremely resilient to close range projectile fire (as witnessed in the episode "Tooth and Claw" when one receives a volley of point blank musket fire, which has no apparent effect on it) however they do appear to have a slight aversion to mistletoe.