I'm stuck on the same exact quest!!! Killing a crab on Port Royal will not give you the thing for the tattoo needle, I killed one and it didn't list it as complete in the quest menu. As for scorpions I know there are some buried in Tortuga but they are deadly and there are skeletons with them as well. I tried to kill some and died. Where were the ones you killed, and where are there giant crabs? I have only seen the crabs on Port Royal and the rock crabs on Tortuga.

I'm also working on those crabs and scorpions right now. I found the doll with it's "special feature" kills the scorpions quite well while you just stand back and watch. Sure wish I had checked to make sure it was complete before going all the way back to Tortuga (I killed them on Port Royal) because you need five of the scorpions. The skeletons aren't so bad, they don't seem to want to engage you so just don't run too near them and they stay away for the most part.

If you haven't already, get a doll, it kills everything so much faster than a cutlass.

I've had no luck killing the crabs, my cutlass doesn't even touch them and then I couldn't engage them at all so I'll try tomorrow.

I'm at the same point on that quest too. Thanks for the tip about the doll. I have a doll, but haven't tried using it yet. How does the special feature work? Are the scorpions on the beach?

I figured out that you can't engage the crabs until you are up to their level. For instance, the crabs that are right near the dock in Tortuga are L4 or L5. There are two further down the beach, but since they gang up on me, I haven't been able to kill them both.

When I was exploring around by using the map to jump to different islands, I discovered what appears to be crab island. If you think the crabs on Tortuga are big, just wait until you see some of those. For someone who has now developed a very strong disliking to crabs with this game, it felt like I landed in a nightmare.

LOL! I har you on the crab nightmare. I've gone exploring too and found the treasure chest awaiting Will Turner's drop of blood.

Use the doll the same way you do your sword, with the mouse, you'll see if you're doing it right because the effect is immediate. Also, it levels up very quickly and is strong that the cutlass. I love that dang dolly! Also, you'll look really cute running around holding it out in front of you.
Remember to go to your weapons panel, if you haven't already, and equip the doll first.

I haven't killed any of them yet, but when you're on Tortuga (on the dock facing the island) walk into the forest on the left and there are some giant crabs in there. Level 9 or 10 I think, and both gang up on you.

Maybe the big clue for us is that we need to gang up on the crabs just like they do to us. Otherwise we keep getting clawed by one while we're fighting with the other one. Anyone want to go crab hunting with me?

Are all these quests named after a ficticious pirate in the game?

no they are not

Do they say Giant Crab? I have run into many types of crabs but so far none have said giant. I was able to kill a few but it didn't complete my quest. I also found BATS!

Isla Cangrejos
 

Is the island of GIANT crabs. Not only are they big but level nine and better. I'm headed over there now to try again if anyone wants to try. I have searched far and wide and this is the only place I've found the ones that say giant. has anyone found any that are a smaller level?

I think Orinda LeJeune is walking in front of the dock on Tortuga

I have found many bats. And yes, the crabs said "Giant Crabs."

Good, then we know that the scorpions and the crabs are in the same swamp. Now if we could just get them to keel over....

The giant crabs are in the swamp on the left side of the docks on Tortuga. I got lucky and killed a level 10 with my flintlock. finished the quest and am now looking to maroon a navy sailor but have no idea how to do it.

My flintlock disappeared... the crabs ones in the swamp have been the ones I've been talking about the whole time...