Ok, for thise who are interested, here's a quick run-down of the 'Slayer' badges and how to get them.
The first 5 badges are for killing specific mobs - Ancient Krayt, Gorax, Kiin'Dray, Overlord and Acklay.
The others are all composite badges made up of others. So the first one is Rodent Exterminator (or something). To get that, you have to complete the slayer collections for womp rats, voritors, etc etc (about 5 or 6 different species for each), and each of those ones is made up of killing, say 200 normal womps, 150 tough ones, 100 gitty ones and 75 low-spawning elite ones.
Some slayer collections can be started simply by killing a required creature (I've noticed that with gurks, peko-pekos and skreegs), others need you to talk to a collector npc (one in Aurilia gives the krayt one) first.
I was trying to solo them as and when I could, but from my experience last night hunting tulruses with Mart, it really is a better plan to do it as a group. Seems like there are a few people interested, so we can probably knock a few of these out together (things like Rill Wrecker you can do on your own though :p)
