After doing some research and trying for the Toothmaul Gully achievements, I decided to make a thread mentioning a few things I experienced, because there is some inconsistent information about the place.
- You don't have to kill all of the champions to make Bloodroot appear. I'm sure his respawn timer is very long, and I got lucky, but I had encountered only 3 champions when I killed all of the spriggans, and made Bloodroot appear on the first try.
- The Gully's denizens can set off bear traps. I only saw it once, but it was pretty funny, because he was wounded and ended up killing himself. The info isn't practical, but I found it amusing.
- The achievement related to killing the champions is not working correctly. I recorded myself killing 5 of them, but only received the achievement for killing three. I don't know which ones didn't register properly, but I know that Togga the Skewerer did register, because it was after killing him that the achievement popped up.