This ancient Pokémon possessed 10 tentacles, which it used to swim through the ocean.
Dark Omanyte was the first Pokémon that is the lowest stage of its evolution family in the Pokémon games to appear as a Dark Pokémon card (though, due to "evolving" from Mysterious Fossil, the card counts as a Stage 1 Pokémon in the TCG). It also has the lowest HP of any Dark Pokémon. The Water Cannon attack was mistranslated for its English release. It should state that the damage is done to the chosen Pokémon. The way the English print is written, the damage is done to the Defending Pokémon, regardless of which Pokémon the user chose.