Q-la , The Demon Heart
A envoy that was previously under contract with Page Claus , but while fighting Enchu in the gardens on Elysium, Ginji accidently took ownership when he told her he would do anything to assist Claus, whom at this time was losing much blood.
Q-la took this as a verbal acceptance of a flesh and blood contract, which was much to Ginji’s displeasure when he discovered later what Q-la had done.
Q-la has the ears and the tail of some sort of dog, and also the fangs.But she is apparently a blood drinker.
At the end of volume 15, she was still lurking around , much like how kiriko hung around.