The Catapult was a submarine used by Douglas Bullet.
Ship Design and Appearance
The Catapult was a very large submarine made nearly entirely out of iron, with a design similar to that of an Island Whale. It was completely grey with only a large red '9' stenciled on the front, and the name 'Bullet' painted along the side, between the pectoral and tail fin. On its back was a structure resembling a normal submarine. It was filled with various weapons.
In the movie, Douglas Bullet used the Catapult as the core of his Gasha Gasha no Mi ability. When he used Union Armado on it, it became a giant gray humanoid robot, with a small head in comparison to the massive body and a spiked spine and tail. Though Bullet mainly used brute force, he was also capable of creating cannons from its palm. Its size exceeded even that of Capone Bege's Big Father transformation.
Four Emperors Saga
One Piece: Stampede
After Bullet is driven back by the members of the Worst Generation, he breaks open the island they were battling on to reveal the Catapult, which he promptly uses his ability on to turn it into a giant robot. With it he manages to quickly wipe out the Worst Generation. As he is about to finish of Luffy, he finds himself being under the constant yet seemingly ineffective fire of Usopp's Pop Green. As he reaches out for the sniper, one of the seeds grow into a vine snapping one of the Catapult's fingers. In the end, he decides to dispose of Usopp by growing a cannon out of it's palm and firing it at him.
Bullet then uses his awakened ability to absorb all the ships around the island, to create a giant monstrosity of his control, with the Catapult and himself at the core. After his rampage is stopped by the combined forces of Luffy, Trafalgar, Smoker, Boa Hancock and Sabo, with assistance from Crocodile and Rob Lucci, Luffy managed to expose the Catapult with his Gomu Gomu no King King King Kong Gun. While the attack wasn't enough to destroy it, it did cause an impact strong enough to grow the Hebi Hanabi Pop Green's that Usopp planted on it earlier. These quickly grew into thick powerful vines, that ended up restraining and snapping the Busoshoku Haki coated Catapult into pieces, exposing Bullet to Luffy for their final clash.
- One Piece Movie — One Piece: Stampede, The Catapult makes its first appearance.