The Knautilus is a particular submarine operated by Baron K. Roolenstein (King K. Rool in disguise) and it is where the final battle of Dixie Kong and her cousin Kiddy against him in Krematoa. It is featured as the final level in Donkey Kong Country 3: Dixie Kong's Double Trouble!.
This sub has the fish form, inside contains missiles, ship's wheel, two large radars in walls, 2 hatches, scuba suits, torpedoes, control panels and five generators. Also contains trap including: fireball cannons, 4 electrical lamps and a conveyor belt.
When K. Rool was defeated in Kastle KAOS, he fell in a wooden well and to his submarine. Knautilus appears in Krematoa's central lake when Boomer starts a machine activating volcano.
- The name is a pun on the name shared by both the Nautilus submarine (from the the novels Twenty Thousand Leagues Under the Sea and The Mysterious Island), and Ursula's Necklace (from Disney's The Little Mermaid).
- If the Steel Keg absorbs the electricity, the game can be paused and then undone for it to be done quicker.
- If the player pauses it while the electricity is still airborne, he/she loses a Kong or a life.
- The GBA version's intro of the game could possibly be a depiction of how Donkey Kong and/or Diddy Kong were captured by the Kremlings, since the intro starts with a P.O.V. shot of someone wearing a diving mask, which ends with the Knautilus closing in and "swallowing" the camera, and then the next shot shows the Knautilus rising out of the water.