Inosuke was raised by that boar and its herd deep in the mountains, learning to survive with the instincts of a wild animal. This explains why Inosuke “always wears his signature boar’s head ...

There's something about a guy wearing a boar head, wielding two blades and jumping into battle. Not only does Inosuke have two blades, but they're carved in a way to give a saw-like appearance.