I have a dog following me, and it talks. I went on a mission in Falkreath to find a guys dogs. If you don't finish that quest, the attack dog always stays with you and is invincible since its a quest item.
Great for tanking enemies (like dragons) while you hit them from afar, but that dog... he is the most co-dependent dog of all time. Outside of combat he can't bear to be more than a foot from you. In tight spaces this is so goddamn annoying. I've gotten nearly permanently stuck (aside from tcl in console) in closets, and he not only can form a barrier to block you, he can even push you around while you're trying to pick up items, or navigate a slender bridge, or are frozen talking to someone... I finally sent him away until I felt like finishing his mission, despite the advantages of an immortal dog.
Everybody good, plenty of slaves for my robot colony?