You go to the left corner from the pearl and you go in.
Its in the clam in the water maze near the hydra's cave.
The scale is one of the 5 sacred items you are collecting. Also the Giant Pearl that is right outside the Hydra cave.
the hydra is in a underground cave near Poseidon's statue.
Defeat the hydra who is found in a cave in the bottom left of poseidon's water maze.
The Hydra is in his underwater lair. Swim out from the beach to the underwater maze, then go right, down, and left to find the Giant Pearl and the entrance to the Hydra cave.
The pearl you need is the giant pearl. Once you use the starfish (from Poseidon's statue in the museum), you can enter the realm and swim through the underwater maze to the cave of the Hydra. Before you enter, get the pearl from just outside the cave.
The giant pearl is just outside the Hydra cave in the underwater maze. Dive into the dark water below the Poseidon statue, then go right along the top of the maze, down the right side, and left to the cave.
Go to the underwater cave of poseidon, then search for the clam.Land next to it without getting bumped,then when it opens it's jaw quickly click on the pearl!
She is called a Sphinx. She is not to be confused with the Minotaur (in the cave behind her) of the Hydra (in a cave underwater in Poseidon's Beach).
Go to Poseidon's realm, using the starfish (from the Museum statue) on the altar in the temple. Pass Aphrodite's test and enter the water. Swim right along the top, down the right side, and left on the bottom of the maze to reach the Gnarly Monster Cave (the Hydra). Up and right of the cave is the Giant Pearl.
The Hydra is a large, five-headed monster that lives in a cave in Poseidon's realm. You must travel to the underwater realm and make your way to the Hydra (gnarly monster) cave. Beat the Hydra by jumping up when it tries to strike you with one of its heads. Landing on top of the head knocks it out. When all five are beaten, swim down and take a scale from the beast. Note : the Giant Pearl is just outside the cave.
The item from the Hydra is a scale, not a hair. The item from Cerberus is a whisker. Find the Hydra cave in the underwater maze in Poseidon's realm. (The giant pearl is right outside.). Knock out the Hydra's 5 heads one at a time by jumping up when he tries to hit you, and landing on the head. Get a scale when he is knocked out fully.