This article is from the 2006 series of SMBZ and is no longer canon.
The Yoshi Chief is the chief of the Yoshis, hence his name. He was the one who discovered the purple Chaos Emerald on Yoshi's Island, and was also responsible for letting the Axem Rangers X get the Chaos Emerald. His people were then enslaved to the Axem Rangers and forced to dig for gems. When Mario and crew arrived, he attacked them due to his distrust of visitors, but after seeing Mario, stops the attack. He was the Yoshi who helped Baby Mario in Yoshi's Island, as revealed in Episode 5. After enlisting the help of Mario to free his people, he took the rest of the Yoshis and evacuated the Island as the battle for the Chaos Emeralds became to heated and eventually led to the Island being destoyed.