A while back the rewards for the 1-star Kraken on the western seas map was changed to possibly give voodoo masks as a reward. I have never received a mask from this target over countless battles. Is it possible that for long time users, this update didn't have any effect? I ask because there have been other similar discrepancies for some of us long time users.
I can't remember ever getting a mask from it either. I gave up battling it months ago. I go after the 2 star Krakens when farming masks.
I believe I have gotten them from it, but the drop rate is incredibly low (c00ni keeps more detailed results). The 2* kraken is much better, I get around a 20-25% drop rate on it.
There is a 'Mighty Kraken' (Green) that has the Voodoo Mask in the #2 slot (currently at H19) on my map. I find that this one usually has a great drop rate and I always include it on any journey.
I agree with Ian, the 2* Kraken do have a decent drop rate. Even though I no longer need voodoo masks, they are one of the two mats I am currently actively farming. As Skye has mentioned several times, short trips are the best. I rotate short trips (usually between 20 and 75 minutes) farming 2* kraken for masks on the western seas with short trips (60-90 minutes) farming ink from merchant ships on the eastern seas. Between every trip, I gem rush (usually between 2-12 gems) short trips on the western seas of ships not in the current path of my planned kraken voyage. These trips almost always gives me battered chests. For me, it seems a deal to be able to buy battered chests at around 5 gems each. For those who can't bring themselves to spend the gems rushing, these short trips are very valuable for obtaining chests. I have completely adopted Skye's suggestion of doing short trips only (except overnight) for farming chests and mats when a wide range of mats are the goal.
Not sure if it helps, but wierd enough as it seems, I just got a Voodoo Mask from a 5 Star Merchant Ship on Western Seas. I try to extend my sea explorations as long as I can in dark waters, more rewards pop up on my maps
