arumajiro アルマジロ

Translation

arumajiro means "Armadillo" in English.
It's a katakanization, a loan-word.

ヨロイネズミ

yoroi-nezumi means "Armadillo" and includes the word nezumi ネズミ, which means "Rat" in Japanese. Note, however, that Armadillos are not rodents.

arumajiro is normally written with katakana, as アルマジロ.
arumajiro written with hiragana is あるまじろ.

Beware: some kanji that are difficult to handwrite are easy to type on the computer, which may skew the usage statistics.