lap dog
1. Literally, a dog that is small enough and temperamentally inclined to sit comfortably upon one's lap. We always had lap dogs when I was growing up, so I never feel comfortable around my boyfriend's gigantic St. Bernard.
2. A person who is readily inclined to submit to, seek the favor of, or agree with someone else, especially a person of higher authority. It sickens me to see you be a lap dog of your boss like that. Have a little self-respect!