Remora

Named after "that little fish that swims with sharks", the Remora is a prototype submarine developed by G.I. Joe that is sometimes a single seat vehicle and sometimes is big enough for at least 5 people to stand up and move around comfortably inside. What technology G.I. Joe used to accomplish this is unknown. In its larger form, the Remora is equipped with a Seapup drone.

Fiction

The single seater prototype of the Remora was tested by Shipwreck at The Pit's underground lake. While the test started off promisingly enough, the sub's port-side ballast tank didn't open, causing the Remora to roll and crash into the bottom of the lake as the cockpit began filling with water. Before Shipwreck could drown, however, new Joe recruit Cover Girl came to his rescue and released the starboard ballast manually, causing the Remora to flip right-side up and float back to the surface. The Betrayers Part 1

The larger version of the Remora was stored on board the Terrapin. When the Terrapin began picking up some gigantic underwater ship on sonar, the ship's captain had Shipwreck and his crew take the Remora to investigate. Discovering the Cobra submarine cruiser Dreadnaught, Shipwreck had his crew get the Remora ready for "deep running", sealing up all of the sub's observation ports as they went in for a closer look. Releasing the Seapup drone and discovering a Cobra drone dropping a nuke into a nearby trench, Shipwreck radioed the Terrapin to alert them to what was happening before attaching the Remora to the Dreadnaught's deck so they could storm the larger sub and stop the nuke from being detonated. G.I. Joe vol. 1 #20

The Manatee submarine reminded Torpedo of a larger version of the Remora. Crush Depth, Part 2

Notes

• While it is never stated to be the same type of vehicle or shown to share the vehicle's trademark ability to fly, the Remora does somewhat resemble the classic Joe vehicle the S.H.A.R.C..
• Given the Remora fish's ability to attach to larger fish, the ability the Remora submarine shows with attaching to the Dreadnaught may be a more appropriate source for its name.
• No explanation is ever given for the discrepancy in size between the Remora's two appearances.