Based on the search results and current trends in comedy, here are nine active comedians known for their insult comedy:

1. Jeff Ross: Known as the “Roastmaster General,” Ross is a prominent figure in insult comedy and regularly performs at roasts[3][4].

2. Lisa Lampanelli: Often referred to as the “Queen of Mean,” Lampanelli is recognized for her sharp insults and roast performances[3][4].

3. Anthony Jeselnik: Known for his dark humor and offensive one-liners, Jeselnik’s Netflix special is recommended for fans of insult comedy[3].

4. Jimmy Carr: Recognized for his edgy one-liners and dark humor, Carr is a prominent figure in British insult comedy[3].

5. Don Rickles: While he passed away in 2017, his influence on insult comedy is still significant, and he’s widely considered the master of the genre[4][5].

6. Tony Hinchcliffe: A rising star in insult comedy, Hinchcliffe is known for his sharp wit and controversial material[4].

7. Triumph the Insult Comic Dog: Created by Robert Smigel, this puppet character continues to deliver biting insults in various comedy appearances[4][6].

8. Bill Burr: While not exclusively an insult comedian, Burr is known for his aggressive style and sharp insults[2].

9. Jim Norton: Often engaging in insult battles with fellow comedians, Norton is recognized for his quick wit and mean-spirited humor[3].

These comedians represent a mix of established names and emerging talent in the world of insult comedy, each bringing their unique style to the art of the put-down.

Citations:
[1] https://www.cracked.com/article_36058_the-best-meanest-moments-from-the-hollywood-reporters-comedy-survey.html
[2] https://www.youtube.com/watch?v=GVxcj7Yc-bM
[3] https://www.reddit.com/r/StandUpComedy/comments/5vpbv3/what_are_your_favourite_insult_comedians/
[4] https://en.wikipedia.org/wiki/Insult_comedy
[5] https://www.thetoptens.com/people/controversial-stand-up-comedians/
[6] https://www.liveabout.com/top-insult-comedians-801871
[7] https://www.instagram.com/mrmentor32/reel/DEjMcH_NSgE/
[8] https://www.youtube.com/watch?v=biwreZcWleI