Koga Takuza was both the founder and the original leader of the Foot Clan in the 2012 animated series. Koga was mentioned in the episode The Legend of the Kuro Kabuto. He was said to be the greatest warrior in Japan and forged the Kuro Kabuto (more commonly known as The Shredder's helmet) a valuable helmet from his defeated enemies' sacred tokens.
Koga Takuza was a legendary ninja who lived about 1500 years ago. According to the Shredder, Koga Takuza was a feared and powerful swordsman. He was capable of easily defeating every samurai he encountered with only his katana. Every time he killed his opponent, he would take their a piece of their armor as a token. After taking a certain amount of tokens, Koga then forged them together with an indestructible alloy that was said to be harder than steel. The helmet was then titled the Kuro Kabuto. After which, Koga created the Foot Clan. Koga would also wear the helmet to both let people know he's the leader of the Foot Clan, and to strike fear towards everyone he encounters.
Before he died, Koga gave the new leader of the Foot Clan the Kuro Kabuto. Every time someone was appointed the new leader of the Foot Clan, the previous leader would give the helmet. The Kabuto has since become a symbolic object of immense value for the order, which must be protected by the current leader of the Foot Clan with his life. This tradition was held all the way to Oroku Saki, aka the Shredder, who is the current leader of the Foot Clan.