The Chameleon (カミュレオン号 Chamaeleon) is a ship owned by De Loco. Like its namesake, the Chameleon transforms at various times, though through parts replacements. De Loco persistently pursues Vyse while releasing new weapons one after another.
Chameleon is most likely a mistranslation of Chamaeleon. All the Admiral's flagships are named after constellations, and as such the constellation's name is Chamaeleon, not Chameleon.
This can be pushed further in how its name is spelled in Japanese. In Japanese, the ship's name is spelled カミュレオン, as opposed to カメレオン, the latter being the usual way of spelling Chameleon.