From the Super Mario Wiki
“Derr...No matter what you hit me with, you can't knock me down!...I think.”
—Ankoopa, Mario & Luigi: Superstar Saga
before and after the fall
Ankoopas are gigantic, pudgy Koopa Troopas found only in Mario & Luigi: Superstar Saga. Their oblong shells extend up from their backs, behind their heads. Their name is a combination of the words "anchor" and "Koopa". They block paths and recite the line: "Derr...No matter what you hit me with, you can't knock me down!...I think." However, Mario's Firebrand Bros. technique can knock these giant Koopas down. To master the Firebrand, the brothers must first visit the Jellyfish Sisters in Gwarhar Lagoon. An Ankoopa also appears in a house in Beanbean Castle Town.