You have a Lifebird, Wrennie! I used to see Shrikes all the time here, but they appear to be vanishing from Tennessee. The last Northern Shrike I saw was about TEN years ago. As I watched it , it flew down, caught a LARGE grasshopper, then flew up and stabbed the body on a barbed wire spike and proceeded to tear strips off the body and eat them. This is CLASSIC Shrike behavior and has earned them the name, "Butcher Bird". It was the FIRST and ONLY time I had actually witnessed this behavior, and it was the LAST time I saw a Shrike.
Like Wrennie said they look like a Northern Mockingbird on steroids, with a Zorro Mask. We have the LOGGERHEAD Shrike here in Tennessee: Wrennie has the NORTHERN Shrike, but the two species are VERY similar. I haven't taken ANY pictures of a Shrike, yet, but found some GOOD ones on Google Image Search