There’s definitely some debate over what the “original” tactical folding knife is. However, it usually comes down to just two options.
First, there’s Bob Terzuola’s ATC, which the lauded knifemaker penned while working for the CIA. The second is Ernest Emerson’s A-100, which was initially crafted for the US military. Whichever side of the aisle you stand upon, there’s no denying the influence of both of these knives.
Now, the latter is getting a pretty stellar Japanese-inspired upgrade in the form of the Emerson A-100 Tanto Flipper.

Bushido blade
The original A-100 (versions of which are still in production) had a spear-point blade crafted from 154CM steel. However, this version swaps both the shape and material.
This version gets a Japanese-inspired tanto blade with a more aggressive, angular piercing point instead of a spear point. According to the brand, fans and customers have been asking for this swap for a while.