(above: 18th century Katar)
It looks super awesome because it IS! Most commonly known as a Katar (Kattari or Katara), this large knife is also referred to as a push dagger or punch dagger because of the particular way in which it is used. Ranging from 1 to 3 feet in length, the dagger is light and acts as an extension of the arm for swift, strong punches (often reinforced by the ability to throw ones body weight into the punch) which were capable of piercing various types of armour including mail and even plated armour.
The weapon originated in south India (possibly as early as the 14th century) and eventually spread throughout the whole of the country. It could be used as a self defense weapon but was often toted as a status symbol with many of the weapons being adorned with gold and jewels.
Its unique design is very functional. The handle consists of two parallel sidebars which are joined by two (or sometimes more) perpendicular bars in the middle that are to be grasped in a fist. It is only really practical for close combat and could be used in conjunction with a sword or another katara as is suggested by some forms of Indian martial arts. The earliest versions of this dagger sometimes have hand covers over them but its seems this fell out of practice in later designs (around latter half of 17th century). The blades are double edged and usually a little thicker at the tip in order to provide maximum blade strength, thus making it capable of piercing armour. In the south it is typical for the blades to simply be straight in design but it is not unlikely to see designs from the north that are wavy. Sometimes you even see designs where the blade spits in two or three (though sometimes because of the hinges most require, these are more decorative than practical) and some have even gone to the lengths of having 2 small pistols on either side of the blade to deliver the final blow but again this probably didn’t work all the great in practice.
After the British colonization of India, the Katara was brought over to England but mostly for decoration rather than to be used and they would often be very elaborately decorated (see this example from the British Royal Collection
The Katara also came under another name, the Bundi dagger, because a special group of them made in Bundi, Rajastan were shown a large exhibition in London in 1851 and thus they earned the nickname. However, this is much less used and considered be an incorrect name.
For further reading see: http://books.google.com/books?id=Px5E3EIF5jQC&pg=PA134&dq=indian+fist+dagger&hl=en&ei=cSfAToPqFMXy0gG67-j1BA&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDkQ6AEwAQ#v=onepage&q=indian%20fist%20dagger&f=false