Ask HN: What are good bad HTTP clients you use?

What are good "bad HTTP client"-s you use to test your HTTP servers? For instance, there are servers like 1) https://httpbin.org/ 2) https://badssl.com/ which allow you to test client against different, sometimes intentionally bad, behavior. I seek for intentionally bad HTTP client, which will send wrong Content-Length or close connection in the middle of request, etc.