I might be completely uninformed but i can hardly imagine Robber Crabs appear in West Sarutabaruta... Please teach me or correct this in the list above, thank you.
The rock lowers on its own about every 15 minutes. It stays down for 30 seconds to a minute, then blocks your way again. Should be long enough to get in, pop the chest and get out.
Be forewarned, there is frequently an Ovinnik (tiger type mob, aggroes to sight) near the top of that ramp which is XP fodder for level 71-73.
Sand Lizards in Kuftal definitely do drop this key. I just walked in here, killed my first one while trying to skillup with friends and got the drop. :P No TH in the party, just three lucky cats. Can't send a correction from this computer, so just observe this post.
I'm only a 53 Samurai, but I got this key and since we are doing other people's 54 gloves soon, I thought I might as well try to find mine before we do. So I loaded up on silent oil, printed the maps out, and in I went.
The place is scary because there's not very many places to recast sneak. The crabs and sabotender are all over the place.
Within the first few minutes I became unable to follow myself on the little print out I had, but I pressed forward anyway. I passed a group of 3 high levels skilling up on crabs, and I stop in front of em to ask politlely if they had seen a coffer. They didnt' even respond. Kinda made me mad that they wouldn't even give me the time of day, so I gave them a /angry and moved on.
I found myself on a decline heading deeper into the tunnel, I'm tabbing for the coffer, when my cursor lands on the one thing I was hoping it wouldn't find....Guirve. And there it was, stupid massive dragon charging up the hill that I'm going down. I wasn't invised, and I imagined that it probably had True Sight anyway, (does it?) so I sped back up the hill and found a little outcropping. The dragon marched right past my little outcove and I readied my warp scroll.
I hope it ate those high levels alive. I'm gonna try and go back today, but I imagine it's still there. =/ Nobody freakin kills that thing, I understand it doesn't drop much of value. But regardless, aren't there enough bored level 75s to wanna take out an HNM? =P
This coffer was a real pain for me, I went looking at least 3 times for long periods of time trying to find the blasted thing at each spawn point. I did finally got it though. Good luck to all those hunting it. I'm not looking forward to the Temple of Uggalepih coffer at all ><.
I thought AF2 was the ??? and beat the NM tiger in Battalia Island. Besides that, the closest thing may be the Coffer key for Quicksand caves for the Drachen boots. Any input on this?
Even without a THF w/ TH2, this appears to be a fairly common drop. While chaining crabs in Kuftal Tunnel, we noticed the frequent drops, so we decided to find an approximate drop rate. In the first 20 crabs it dropped 4 times. The next 20 it dropped 3 times. 7/40 crabs is not bad compared to some of the other coffer keys that are hunted for. From what I understand, this coffer key is also used to obtain the map for Kuftal Tunnel, but I'm not sure. I'll update this post once I find a definite answer.