Clearly a nod to Colonel Trautman from Rambo, the Trautman Knife is the fourth knife to be unlocked and is based on Rambo's bowie knife. It has the highest damage and range out of all the knives. However, it has the slowest charge time of the knives.
The Knife is clearly based on the one used by the character John Rambo from the movie series Rambo, which is a large Bowie Style blade, with the serrated edge on the back and a compass in the the pommel of the knife. The only real difference between the Trautman knife and Rambo's own is the green paracord wrap on the latter's hilt instead of the former's black.
The name is also clearly taken from Col. Samuel Trautman, Rambo's mentor.