Nomming the Madsens as a group would make a lot of sense, since there isn't much in the way of canon material to distinguish them.

Re: Kitty, I'd put her down as "Crew Cat" or something like that, myself (she doesn't seem to have a set ao3 tag at this moment). But you make a good point about whether animal characters are allowed - I'm pretty sure that intelligent/talking ones like the aRTD haltija characters are within the guidelines, but someone like the SSSS cat, not sure....