A walking tank with a heart of gold, the Rottweiler struts onto the scene like he’s charging an entry fee. He’s the kind of suspect who can look menacing enough to scare off a biker gang, then immediately flop onto his back demanding belly rubs. Furniture isn’t furniture to him — it’s territory, and if he sits on you, congratulations, you’ve been annexed. The Rottie operates with two modes: intimidate the intruder or drool on the owner’s lap, sometimes both in the same minute