Dog

Throw a dog (d), or cat (f) some tripe, a fortune cookie or something else that it will eat, such as a fresh corpse, and it will become tame (your pet).

Dogs are better fighters than newly started characters, use them to tank and fight for you in the early stages of the game. Nevertheless, they may be more vulnerable than newly started characters against corrosive monsters that splash acid. They also appear to be naïve to the ways of floating eyes.