Elite X-Naut

Elite X-Nauts are high-ranking soldier X-Nauts and, of course, the strongest X-Nauts. Unlike the Trooper X-Naut or the PhD, this type of X-Naut wears a red-and-black uniform with a white X to signify their rank. Judging by their rank, they are usually sent on special missions. One of their usual tasks is guarding their Headquarters on the Moon. The Elite X-Naut is much tougher in battle than a standard X-Naut.

The first time Elite X-Nauts are seen on The Moon, two of them attack Mario so they "can get all the credit for defeating Mario". This was taken from the first Paper Mario game as two Koopatrols had the exact same conversation.