How do you open the door to giant crab in hungry shark evolution?

You can't actually open a door to the Giant Crab in Hungry Shark Evolution.

The Giant Crab is a boss enemy that you encounter in specific locations in the game, primarily in the "Deep Sea" and "Lost City" levels.

Here's what you need to do to encounter and defeat the Giant Crab:

1. Reach the required level: You need to have your shark at a high enough level to be able to access the "Deep Sea" or "Lost City" levels.

2. Find the Giant Crab: These levels have specific areas where the Giant Crab spawns.

3. Engage in battle: Once you find the Giant Crab, you'll need to attack it.

4. Use your shark's abilities: Use your shark's bite, boost, and special abilities to deal damage to the Giant Crab.

5. Defeat the Giant Crab: The Giant Crab will be a tough opponent, so you'll need to be strategic and persistent to defeat it.

Note: The Giant Crab does not have a "door" that you can open. You need to confront it directly in its environment.