Time Bokan Series: Yatterman (1977)

A mysterious gem called the "Skull Stone" is said to be able to reveal the location of the largest vein of gold in the world. This legend has entranced many people who wanted to get their hands on fame, power and wealth, including the trio of villains in this show: the "Dorombo Gang." However, their hunt for the Skull Stone is not as easy as they imagined, mainly due to the faulty information they receive from their leader, and most of all, by a justical duo of pursuers called the "Yatterman"! (Source: Wikipedia)