Hound's Swiss Army knife

Even a big bot like Hound carries a Swiss Army knife around. You just never know when something like that would come in handy.

Fiction

Hound carried around his Swiss Army knife, but was never seen using it. Age of Extinction

See Hound (Movie)#Toys

While all of Hound's weapons originally went unnamed in the films and toy releases, the name comes from concept artwork and weapons references used in Age of Extinction.
While not an actual weapon in toy form, it is still mostly present as a molded detail on just about every one of Hound's toys. Sometimes it is even picked out in red paint.
It's unknown if he continues carrying his Swiss Army knife in The Last Knight as the place it stored is now obstructed by a large clip for his vest that wasn't present in Age of Extinction.