How to put someone down with just one word

Remember when we were growing up and our parents taught us manners? Or you wanted to put down a friend or a pest who was acting unbecomingly?

If we "got to big for our britches," or didn't act right, they would tell us, something like, "don't be a spoiled brat," or "don't be a poor loser."

No need for that anymore. One word will suffice for a multitude of pejorative judgments and put downs. "Oh quit being a ---trump."  (lower case please.)

Think of all the instances that will fit. Some version of with, "Don't be a..." or "Quit being so.... " Here are a few that come to mind. Other ideas?

1. Spoiled brat.
2. Liar. 
3. Poor loser.
4. Cry baby.
5. Bossy.
6. Egomaniac.
7. Racist.
8. Con man.
9. Arrogant.
10. Cruel.
11. Name-caller.
12. Deluded.
13. Sullen.
14. Selfish.
15. Self-Centered.
16. Moody.
17. Callous.
18. Impolite.
19. Pompous.
20. Inconsiderate.
21. Dishonest,
22. Narrow-minded.
23. Intolerant.
24. Resentful.
25. Inflexible.
26. Deceitful
27. Machiavellian.
28. Traitor.
29. Full of yourself.
30. Big-headed
31. Braggart.
32. Selfish.
33. Thinking you're entitled.
34. Cheater.
35. Freeloader (not paying your taxes).
36. Defrauder.
37. Defaulter.
38. Thief.
39. Pathetic.