Batman has a staunch stance on guns, which is to say he is completely against them. After all, his parents we’re murdered by one, though it’s arguable that guns don’t kill people, people kill people. So we’re relatively confident that he would fully endorse this Batman Batarang Dark Knight Double Edged Folding Knife.
It comes in a variety of colors, and although it probably isn’t all that practical in terms of self defense, it sure does look menacing thanks to the dueling blades which fold out from either side. Gripping it in the middle, provided both blades are extended, will mitigate some of the risk of getting cut, but given its obscurely shaped handle we don’t recommend it.
The Batman Double Blade Knife comes in red, black, pink, silver, and purple. They start at about $9.
Alternatively, and perhaps a bit more practical, is the Batman Joker Knife. If memory serves correctly this is a replica version of the knife seen in the second film. There are a few versions, but you’d probably be most interested in the spring loaded blade, which supposedly fires open and snaps into place. It costs just $4, though shipping is another $4.