Den

Den is the Rockbell family pet. It is apparent that she lost her front left leg by unknown means prior to the start of the series, as she wears an automail limb in its place. Den is fiercely loyal and, as such, has been called "Resembool's best bodyguard" by Pinako. Den is also particularly compassionate as shown by the way she attempts to comfort Pinako after Winry leaves home to work at Atelier Garfiel in Rush Valley. Unfortunately, Den is put largely on edge by Van Hohenheim's strange aura when he arrives at Pinako's house and nearly has to be restrained from attacking him.

Trivia
Arakawa has revealed in some story notes that Den's name originated from a dog she herself once had, a male dog named Densuke, which means watermelon.