beastly
adjective
Beastly means like a beast, or something that a beast might do. For example, if someone is really angry, someone might say they're being beastly.
Example
1. The child was acting so beastly that his parents had to send him to his room.
2. His temper was so beastly that no one wanted to be near him.
3. His beastly attitude was not welcomed in the group.