While not common, it happens that the God-Machine assigns an Angel to wear an animal's shape. Even more uncommon is that such an Angel experiences the Fall and his identity as an animal is turned into its primary Cover. Familiars have often the advantage that they are overlooked and few suspect that an animal could carry an angelic entity.
While the Unchained retains all his demonic intelligence, he is in a precarious situation. Since animals cannot make Pacts, it has to search for other Demons or mortals and contact them. Doing so always risks compromise, since animals in general do not try to convince people to sign away parts of their identity ( to say nothing about physical limitations, which make writing and signing pacts difficult). It is even more difficult to get people to work with one, since most persons who hear voices from an animal believe themselves insane or rationalize it away. Most Familiars prey on the mentally unstable, using their Endowments carefully and playing the long game to gain access to a more humanoid shape.
- , p.118-119