WARNING: Location spoilers to follow. If you're looking to play through "Dead Island" clean, stop reading now.
Scattered throughout Dead Island for Xbox 360, PS3 and the PC are five colorful and rather nasty looking skulls. Some players have scooped up one or more and forgotten about them. Others have discovered there's more to the skulls than meets the eye.
When found, each of the five colored skulls simply vanish. There's no sight of them anywhere in the player's inventory, which is why many players have written them off as nothing more than neat Easter Eggs for show only.
As some players with a keen eye for exploration and discovery have found, the skulls are willing to offer up a reward when taken to the right location to essentially activate them. To help you find all five of the skulls in Banoi, where to take them and what the rewards are, pay close attention to our Dead Island skulls locations and drop-offs guide in text and videos below.Brown Skull
This skull is best found during the "Black Hawk Down" mission in Act 1, Chapter 3. During this chapter you'll use a manhole cover in the first bunker to access the second bunker. Here you'll find the Brown Skull on a pile of bodies just behind a curtain.
Take the Brown Skull to the coast near ID 004, on top of the small mountain/hill only accessible via wooden planks. Brown arrows along the path will show you the way.
The reward for dropping off the Brown Skull is Developer's 666 weapon recipe that will create the Left Hand of Glova. All you'll need to make sure to have is $10,000 and 5 diamonds.Orange Skull
The Orange Skull is most easily accessed in Act 2, Chapter 6 called "Market Journey." During this chapter you'll find yourself entering a supermarket through the sewer system. Near where you turn off the steam, you'll find a room with a workbench just of a dead-end. Head the opposite direction of this room until you find some stairs. The Orange Skull is in a shopping cart just under the stairs.
You'll need to be back in the sewers to drop-off the Orange Skull at the right location. Use the sewers to enter City Hall and head into the large main room. On the left side of this room, toward the middle, is a ladder. Climb it, enter the first room on the right through a door, and put the Orange Skull on top of the pile to the left.
Your reward for the Orange Skull drop-off is the Developer's No. 1 Craft weapon recipe that creates an electrified knife. To use this beauty you'll need a battery, $10,000 and 5 diamonds.Purple Skull
Find this skull just after the Act 2, Chapter 5 titled "Let the Waters Flow." More specifically, it's located in the "It's Our Own Fault" shrine that you enter near the church. Head through the entrance and take a left at the dead end, near where a pair of green barrels are. Keep going straight and through a gated entrance. It will get darker, but keep your eyes open for a room on the right with a high catwalk. This same room has a ladder that you'll take up to the catwalk where a chest has the Purple Skull.
In Moresby, take on the "Uninvited Guests" side quest that allows access to the abandoned house. There's a stove in the house's second floor that you'll want to use to deposit the Purple Skull.
Your reward is the Developer's No. 4 Craft weapon recipe that will build the Military Knife. It requires the usual battery, $10,000 and 5 diamonds.
Remember the room where you just dropped off the Purple Skull? The Blue Skull is located in the room just across from the room where that skull was. You'll find it perched atop a cabinet shelf behind glass.
Once acquired, take the Blue Skull to where the game started and head south toward the beach. You need to be far enough along in the game until you hear Jose Garcia yelling for help. The bunker here previously locked will now be unlocked, so you can enter and take the warp inside. You'll find youself in a graffiti-filled bunker with a ladder. Take it, then use the propane tank to blow up the door to the right. The skull drop-off location will be obvious in the next room.
The Blue Skull will reward the Developer's No. 3 Craft weapon recipe for the Plaguebearer Military Knife. To build this toxic knife you'll need a battery, $10,000, 5 diamonds, AND 1 oleander.Green Skull
Travel to the Gas Station and head directly east in search of a hill with a sand path around it. Search around the hill for a path accessible only by jumping, and find the Green Skull on the other side.
Take the Green Skull into the Supermarket to the aisle near the Surf Shop area that has toy bears. Look toward the bottom of the bears for the one where you need to drop off the Green Skull.
The Green Skull drop-off reward is the "Cr33zz Revenge For Endless Crunch" baseball bat recipe, and will set you back a battery, 5 diamonds and $10,000.
Are there more Dead Island skulls to be discovered? Not likely, but if more are discovered then I'll be sure to pass along the locations and info.Source: http://www.thehdroom.com/news/Dead-Island-Skulls-Locations-and-Drop-Off-Guide/9501