Translation

yama-arashi means "Porcupine" in English.

yama-arashi is normally written with katakana, as ヤマアラシ.
yama-arashi written with hiragana is やまあらし.
yama-arashi written with kanji is 山荒.
These are jouyou kanji 常用漢字, taught in junior high, chuugakkou 中学校.
Romaji ya ma a ra shi
Hiragana
Katakana
Kanji
Meaning Mountain Storm
School Level 小1

yama-arashi may also be written as 山荒らし or 豪猪.

Further Reading

Wikipedia: ヤマアラシ (Porcupine)
yagi 山羊.