Is Frinos the only one so far?

!Right up until I got the animal treats, I saw that cat every time I hit the Erebus fountain. But I have not seen it since and finally caved and gave my only treat to Frinos. I thought that maybe once I was able to use the stardust to make more treats, the cat would show up again, but so far nothing. Is this because: 1) Frinos is the only familiar, so the cat is hiding until the update; 2) the RNG hates me; or 3) there is an additional trigger I am missing?!<

!Also, bonus question, are there any other animals beyond Frinos and the cat?!<