This item is a very simply animated Rottweiler Dog Prop for use in movie making.  Originally built for "Batman, the Dark Knight" (2008).  After using this action prop, the film's director, Christopher Nolan requested a more animated attack prop.  Kris Peck, Prop Master on the show, then specified that better Rottweiler Dog Attack rig which is shown here. 

A double controller like this one is required to animate the prop.  Controller cabling and testing prep work is available also.