Once you enter Shark Tooth Island, go right to talk to the man in front of the Coconut Cafe. Click on him, and he will say something and give you Carbonated Coconut Milk. Then go further right to the Ancient Ruins.
Now, push the big stone block until it is underneath the vine hanging down from the platform on the tree. Be careful of the coconuts falling down,, but jump onto the block, then jump up to the vine and climb up. Jump down on the lowest platform, then go to the the platform just above it. From there, you can jump onto the roof of the ancient ruins, then onto get the sheet of torn paper with the code.
Now run along to Booga Bay. Talk to the man wearing a Grass Skirt. He will give you a grass skirt. Go to your inventory (The brown backpack) and put on the grass skirt. Go back to the ancient ruins, and keep on climbing up vines, and jumping up platforms to reach the very top, and talk to the man wearing a blue mask.
You can use all three options, or you can skip directly to ‘What else can you tell me?”. Now go down again, and go inside the ancient ruins. Go all the way down, then go to the left most corner, where you can see something on the wall, which looks like a face, with pointy teeth.
Use the torn paper to press the symbols, in the correct order, as in O P E N. Go inside, and jump to the platform where the fruit Bat Boy is standing. Now take a very big jump to the left, and land on the statue (This may take a few tries because the giant caterpillar can knock you off)
Jump onto the swinging platform on top, then jump inside the place lined with spikes. Go down and get the giant bone. Now go back on to the staue and jump up on the fin, then go on the swinging platform. Now, instead of going dow, jump on to the horizontally moving platform and take a ride to the end. Go left. Run to the left in the little tunnel and jump to the bottom. Run to the left, jump on the platform and get the key ingredient. Climb up the vine.
You arrive at main street. Go to the blue mask man and talk to him. Wait for the key ingredient, bone and carbonated coconut milk be given to him. Once the bone dissolves in the pot, you will be given the sleeping medecine in a coconut.
Go to Booga bay, and go to the coconut feeding machine. Your sleeping medecine will be given to the shark and he will start skeeping. Swim all the way to the right, and get the professor and the boy. they will follow you back to the mainland.
The crying mother will thank you and the professor will give you your medal. Congratulations! You have completed Shark Tooth Island and have got a medal and 100 credits!