Familiars

By tradition,familiars take the forms of beasts, but at the end of the day, a familiar is an extraplanar spirit in the shape of a beast, so why not let them take the shapes of constructs, undead or fey?

Animated Objects

Constructs - and things that look like constructs. Many of these creatures are in some sense man-made, meaning they feel right at home in the company of people.