Jack

He is 3rd in command in every series except for Ninja Thunder were he is 2nd

Original 1-2
He was the 3rd in command

Neo
He controled the Shark Zord (Neo)

Turbo
h econtrols teh Ocean Racer Zord

Astro
He controlled Astro 3

Aqua Rangers
His zord was the Whale Zord

Ninja Thunder
His zord was the Tiger Zord