1. 兽；野兽
    You can refer to an animal as a beast, especially if it is a large, dangerous, or unusual one.

    e.g. ...the threats our ancestors faced from wild beasts.
           我们祖先面对的来自野兽的威胁
    e.g. ...a centaur: half man, half beast.
           半人半马怪物：一半人身，一半兽形

2. 兽性的人；畜生；禽兽
    If you refer to a man as a beast, you mean that his behaviour, especially his sexual behaviour, is very violent and uncontrolled.

    e.g. ...a sex beast who subjected two sisters to a terrifying ordeal.
           使两姐妹遭受恐怖摧残的色魔

3. 讨厌鬼；王八蛋
    If you call someone a beast, you think that they are behaving in a selfish, unkind, or unpleasant way.

    e.g. Bully! Hooligan! Beast! Let me go, let go!
           混蛋！流氓！王八蛋！放开我，放开！

4. （含诙谐意）有特定性质的事物，性格特别的人
    You can use beast to refer to something or someone in a light-hearted way, and to mention that they have a particular quality.

    e.g. ...that rare beast, a sports movie that isn't boring.
           这场体育电影还挺有意思，真难得