As a recolor of Cap'n Crash, Cap'n Rex instead has red skin, white hair, a white moustache and goatee. He instead wears a black bicorn (pirate hat) and captain's coat, and a dark red hakama. His large anchor is now ruby colored and the wraps on it are golden yellow.
"Dorobune Yōsorō" is loosely translated to "Mud Ship Straight Ahead". This most likely refers to an upcoming ship, or that he is commanding the "ship" straight into battle, showing that he has a bold spirit.
The "Rex" in Cap'n Rex's name may be a pun on "Wrecks".