Run up behind it and jump on its left ankle. Stab its weak point; it'll crouch down and this gives you a chance to jump on his hip. If your strength bar is getting low, stand on one of the platforms on his back. Then jump up and keep climbing until you reach its head. Keep stabbing until it dies.
Second: Run around holding your bow on Agro. You will notice green glowing spots on the soles of its feet. When you get the chance, hit it with an arrow. It will fall, so you can climb up either its tail or leg I forgot and take out your sword. There is a weak point on its rear end, and one on its head. STAB HIM!
Third: Run to the circle platform and get him to hit you with his hammer. Roll out of the way. It will smash some of the hammer, showing some hair. Get him to hit you again, and climb up his hammer and onto the arm. Keep climbing until you reach his head and stab him. Then go to the front of his waist. There is another vital there. GET HIM!
Fourth: This dude is a piece of cake. Get him to follow you near one of the little hobbit hole-like things. Walk around in the chamber and exit through a different one. He should have his head ducked under, looking in the hole. Take this opportunity to jump on his tail and climb. There is a wound on his neck. Stab it, and his head will lower. Then get on his head and kill him.
Fifth: This is my personal favorite. Swim around until you reach three platforms sticking out of the water. Get on the middle one and hit him with an arrow. This will make him mad and swoop down to attack. At the right moment, jump on his shoulder, and you're airborne. The weak spots are on the tip of each wing, and one on the tip of his tail.
Sixth: RUN! Run until you reach a barrier with vases surrounding it, and climb over. He will smash it. Keep going until you reach the wall, and duck behind the columns there. Sooner or later, he'll duck under to look for you. Jump on his beard and climb. The weak spots are on his head under his shoulder to the left.
Seventh: Swim around and get his attention. Sooner or later, he'll surface and gives you the opportunity to jump on to him and hang on. Behind each electricity stem thing on him, there is a wound. Stab it to turn it off. Do this two more times until you reach its head. KILLIT!
Eight: Hit him with an arrow to get him to start climbing the walls. Run down a few flights of stairs until you see him and he doesn't see you. Shoot a couple arrows into either his ankles or wrists. This will make him fall. Get to the bottom of the arena and stab him on his belly. This Colossus has two weak spots on his belly.
Ninth: Get him to run after you and get under a geyser. This will make him fall. Shoot an arrow into its two feet and it'll roll over. Run around and climb up its belly and on its stegasauras-like spikes. Hold on tight and run to its head and kill it.
Tenth: Run around on Agro while it follows you. Ready your bow and sit backwards on Agro until you see its orange eyes. Fire an arrow in one and it'll "swim" off and bury its head in the sand. Jump on its back and stab it when you see the weak spot.
Eleventh: Avoid the first charge, then climb up on one of the pillars holding the fires. He will headbutt it, making a piece of wood with fire on it. Jump down and pick it up. This Colossus is afraid of fire, so mak it back up and fall off the cliff. On the fall ,it will lose its back armor. If our timing is right, you can jump on his back and kill him in one run.
Twelfth: Swim until you reach its chest and swim under his armpit and around until you reach its tail. Climb up and to his head. There are nine tooth-like things on his head. Hit the left one with your sword, and he'll go left. And the same for the other two. Guide him to one of those circular towers and jump off. Quickly, hide behind the round stone in the center. Sooner or later, he'll get plucked with you and jump up. Take this opportunity to jump on his belly, where his weak spot is.
When you get enough strength to climb the top of the temple, DON'T EAT THE FRUIT UP THERE IT WILL DECREASE YOUR HEALTH AND STRENGTH BARS!!!