Um, maybe a Claptrap Helmet.
Basically, it has a contraption at the top that looks like a beartrap, kinda. You pull a lamp-type string to open it, and letting go of the string shuts it automatically.
It can be used to clasp things (so swinging your head would allow triple wielding of weapons--one in each hand, one in the helmet).
You could even make it swivel forward and backward, and to either side, to make it a dangerous close-range weapon. And any foe so unfortunate to get his hand caught in it will get a nasty bite.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)