Viser

Viser is a Stray Devil whom Rias and her peerage confronted.

Appearance
At first glance, Viser is a young woman with a voluptuous figure with short white hair, but her lower body is gigantic and beastly with four legs, each having sharp claws, and a snake as a tail. Her overall appearance is reminiscent to that of a Centaur.

In the anime, Viser still retains her voluptuous upper body, although her short white hair is replaced with long, black hair. Her centaur-like appearance has also been slightly altered, with her front legs featuring humanoid hands with red claws (the same color as her sharp nails) and her stomach featuring a cavity with teeth to devour her opponents. In the middle of her battle with the Occult Club, her face changes, bearing pirhana-like teeth, pointed ears, and black sclera in place of the usual white.

Personality
Viser is a ruthless Devil who has an extreme lust for blood, evidenced through her introductory speech. In the anime, she shows some exhibitionist traits, rubbing her bare breasts in pleasure in front of her combatants.

History
Not much is known about Viser, other than at some point she betrayed/killed her master and started to consume human bodies for food.

Plot
Viser was introduced in the first light novel volume when Rias and Occult Research Club were ordered to dispose of her because of her powers going out of control. During the battle, she was incapacitated by Yuto (cutting her arms off), Koneko (punching her in the stomach), and Akeno (shocking her with lightning). Overwhelmed by their power, she was soon confronted by Rias, whom she asks to kill her. Complying with her last words, Rias terminates her using her Power of Destruction.

Powers & Abilities
As a Stray Devil, Viser possesses an uncontrolled amount of power. Her Centaur body possesses superhuman strength, shown when she (briefly) manages to hold down Koneko. She also fights with two spear-like objects.

In the anime, she has the ability to squirt acid from her breasts (with magic circles appearing on her nipples prior to firing), and has the ability to consume her opponents using her stomach cavity from her Centaur body.

Quotes

 * "I smell something bad. But I also smell something delicious. I wonder if it's sweet, or if it's sour?" (Volume 1, Life 3)
 * (To Rias) "You are cunning for a little girl!! I will rip your body and color it in red just like your hair!!" (Volume 1, Life 3)