Poptropica Underwater. It is an episodic island, just like survival island, and the first episode is called into the deep.in this episode, you’ll go deep underwater to the bottom of the ocean on a mission to photograph rare fish. Jump on the hydra's heads when it strikes and when it's completely unconscious, take a scale.
In the game, players, called poptropicans travel to different islands and complete quests on them. Poptropica underwater part 3 full. To defeat it, get close and it will strike out at you with one of its heads.