Magellan

Warden of Impel Down prison, user of the Venom Fruit: his body oozes lethal toxins. Nearly unbeatable, he held his own against Luffy during the break-in.

Warden of Impel Down prison, user of the Venom Fruit and nearly unbeatable within its walls. He poisoned Luffy nearly to death, but could not prevent the great escape nor Blackbeard's break-in.