Captain Koopa Troopa
From the Super Mario Wiki
Captain Koopa Troopa is one of the main protagonists of the Minion Quest: The Search for Bowser story mode from Mario & Luigi: Superstar Saga + Bowser's Minions. His main personality quirk is his tendency to speak in rhymes. Other characters are often annoyed by his rhymes, typically resulting in a drawn-out silence with nothing but wind sounding; Fawful, however, is vocal about how bad he finds them, calling them "unspecial and full of cringe." Captain Goomba, on the other hand, is encouraging of them in many cases.
Captain Koopa Troopa first encounters Captain Goomba, Captain Shy Guy, and Captain Boo in Teehee Valley. Out of boredom and loneliness, he joins the Goomba Squad, even accepting the offer to join as a captain without question.
Captain Koopa Troopa appears in Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, where he is an enemy in the Bowser Jr.'s Journey mode. He fights alongside Captain Goomba, Captain Shy Guy, Captain Boo, and King Bob-omb.