Messy

Retrieval Bot Designate Meson-Zero-Sierra 29 was a robot member of The Empire of Eternal Victory. After being attacked by Rory with a cupboard door, dismantling his arm from the rest of his body, he gave his allegiance to them for defeating him. He helped Rory and Sam to find  the Doctor and Amy.

Messy explained to Rory and Sam that he had been alive before the second Empire of Eternal Victory had begun. But his mind was wiped of the events that happened to the first Empire. (NSA:  Web in Space!)

Features

 * Messy had a waterproof outer casing, because he was actually a plumber.
 * He also had back-up services for travelling through water, mainly a powerful propeller. (NSA:  Web in Space!)