Catty (adjective)

1. Spiteful or malicious.
2. Characterized by a sly or cunning nature.

Origin:

From cat + -y, resembling a cat in some way, such as being sneaky or malicious.

Examples:

1. She made catty comments about her classmates.
2. The catty remarks were hurtful and unkind.
3. He had a catty attitude towards his coworkers.
4. The catty behavior was not tolerated by the group.
5. She had a catty way of getting what she wanted.