Minis from the various Sweeney Todd universes are mini-razors.
Mini-razors have their name engraved on their handle. They apparently move around on tiny little silver legs. They are very aggressive; unlike most minis, they may even attack PPC agents, typically aiming for the jugular vein or other major sites of blood movement. Because these minis actually feed on blood (through the handle, somehow), keeping an adopted mini-razor well-fed is highly recommended. (Animal blood is sufficient to sustain them.)
Sweeney Todd is a barber. He uses razors to shave people.
Sweeney Todd is a serial killer. He uses razors to slit people's throats.
Sweeney Todd sometimes sings love ballads to his razors.