Karka slayer is very quick to do if you know how to do it.
Look for a Veteran Karka mob that can ‘lay eggs’.
Approach and aggro it.
It will lay 2 batches of eggs; wait til they hatch, kill them for about 10 kills.
If you get downed kill the hatchlings to rally.
This is best done with about 2 people just in-case you get killed, but can also be managed with 1. Tone down your aoe damage so you can both aoe tag them.