I like it. However, I find it hard to believe that a non-human civilization would invent or willingly submit to such a "tradition" as tail docking or amputation, much less adopt it from another culture. The Breti and ceorzas would have to want their tails (or children's tails) docked, or else the Breti king is something of a dictator and all his followers agreed with him. What I'm trying to say is that I don't believe any species other than humans would come up with this kind of "tradition". You might want to think about this a little more before you decide you've invented two or more races of animals who seem to want their I'm sure perfectly good tails cut off. Also, if tail docking is being practiced it's not accurate to say the Breti "have no tails". That's like saying cocker spaniels who have had their tails docked "have short tails". It's just not true. They have long tails, but you'd never know. It's sad, IMHO.
Sorry for the rant. I feel strongly about unnecessary surgery, even in imaginary animals. I hope no one else finds that this seemingly small aspect of your conculture overshadows the other more delightful ones.
Edit: And what about painkillers? Won't you be needing those?
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