legendary beast; magical beast
A creature from myth, folklore, or fantasy settings, often possessing supernatural powers or monstrous traits. Common in games, light novels, and anime.
そのゲームでは、プレイヤーは魔獣を倒して経験値を得る。
In that game, players defeat magical beasts to gain experience points.
伝説の魔獣が森の奥深くに住
A legendary beast is said to live deep in the forest.
Compound of 魔 (ma, 'demon, magic') and 獣 (jū, 'beast'). A modern coinage common in fantasy media; not a classical term.