Femur

Femur is one of Lord Loss' Demonic Familiars. So far the demon has appeared in books 5 and 6. It is a warped rabbit like demon of which shoots/spits acid at it's victims which has a deadly affect. During the attack on the plane, Femur aided Lord Loss and took many lives of innocent humans. Femur is killed in book 6 when Lord Loss attempts to open the tunnel, Grubbs Grady uses a powerful magical attack which kills the demon.

Other named demons to have appeared in the books are:

Artery Vein Spine Cadaver Malice Cretin