Lego Atlantis [2010, USA, animation, DVD5]

She briefs the crew on the real reason behind the mission, but before they can voice their displeasure at the farfetched story of Atlantis, the submarine comes under attack by a Giant Crab, the likes of which has never been seen before. But things are about to go from strange to outright bizarre, as the crew finds itself being plummeted to the bottom of an underwater volcano, besieged by a host of mutant sea life, and mentally tested to uncover the secret of the mysterious Glowing Crystals they uncover along the way. It's going to take all their strength, willpower, and brainpower to overcome the unknown elements of the ocean's depths, but if they can survive, they just might discover the greatest treasure the world has ever known... The Lost City of Atlantis.