There are very few rules for what you can and cannot do when it comes to creating a trainer. Trainers must be of 18 years or older, for everyone's sanity, and must be of atleast human intelligence. Other than that- go wild. Have a great time.

Yes there are furries. Yes they can be based on Monsters or real animals.
Yes there are furry-variants (dragons, birds, snakes, etc)
A Human is an option. Do it.I dare you.

"Alters" or "Halfwilds" are a special anomaly where human DNA splices with that of one or multiple species of monster. They may take on the appearance and or the attributes and abilities of their monster(s).