I'm a furry (Been for ~10 years, actually going to a big con in a week) but not a Therian. I too sometimes find some of the Therians a bit, uh, eccentric. But I think it's worth clarifying that most (I think) don't literally believe themselves to be part animal or werewolves or whatever, I think it's usually a spiritual thing, where they so strongly identify with the animal that it's part of how they act and see themselves.

I, personally, find that actually more understandable (as someone that isn't in the group) than I do, say, most religions and their belief in a higher power. That's not to in an attempt to offend or belittle either group (or the overlap, religious Therians), just a view from my particular perspective where it's really no more strange than anything else people do. If it makes them happy, lets them connect with others, etc. who am I to judge?

There are, of course, outliers that literally believe themselves to be shapeshifters or whatever, but, okay? As long as its not impacting their day-to-day too much, many of them are still probably mentally more healthy than a lot of other people.