A courageous explorer, owner of The Zooniverse, Howard Moon's nemesis and more recently a politician for the Sir Digby Chicken Ceaser Party. He is evil in a more deliberate and much less insane way than any other person in the world.
He is a proud man with a deep, booming voice. He seems to succeed wherever Moon fails - be it exploring, writing or moustache growing (he uses his magnificent moustache to get him out of trouble - for example, by hiding a pistol in it.) While the press prints stories of his heroic adventures as an explorer, he is in reality a very sneaky, sinister fellow involved in various shady operations. He experimented on zoo employees to create human/animal mutant hybrids and he imprisoned the zoo's former owner, Tommy, in the Jungle Room for many years. He despises Vince and Howard, but while Howard sensibly despises Bainbridge in return, Vince is sometimes awed by Bainbridge's tales of adventure.
Bainbridge's assistant is Bob Fossil, who has a crush on him, although Bainbridge has contempt for Fossil and often knees him in the groin. Fossil is always hoping to be part of Bainbridge's shady operations, although Bainbridge generally treats Fossil like his lackey. Fossil, while a generally sleazy person, isn't quite up to Bainbridge's standards of evil, and when confronted with the products of Bainbridge's mutant experiments, Fossil was horrified.