Robotnicus

The Robotnicus was Doctor Robotnik's personal luxury airship, on which he threw a party for his nefarious colleagues. He also used the cruise to transport the 'taxes' he'd collected from the citizens of Mobius. The ship was attacked by Captain Plunder and his Sky Pirates (on a tip-off from Sonic the Hedgehog), and the cargo of treasure was stolen. However, Captain Plunder himself was captured before he could escape, and he was arrested by Robotnik's Troopers.