Some "backpacking" bag I had bought - like a Coleman or something. 40 degree bag for a meager 4 pounds and compressed to the size of a 5 gallon bucket. My dog got a running start at it, ran through it like a tunnel and blew the bottom end off of it. A spectacular sleeping bag death, especially since there was a person in it at the time (not me, thank goodness), and a great reason to throw it away. I almost had to throw my good one away (that I was using) because I was dangerously close to peeing my shorts when I witnessed the aftermath. It was one of those times when I was thinking to myself that I really needed to be disciplining my dog but, at the same time, it was one of the funniest things I'd ever witnessed.