so I've been looking around and haven't found a solid awnser to this question. There's probably an obvious awnser I jus cant find. In the riding rat description it states
"A ratfolk with the animal companion, mount, or similar class feature can select a riding rat as her mount."
In pfs, assuming you have the ratfolk boon, is there anything, by raw, that would keep someone from choosing a riding rat as a familiar?