I'm not sure a real bestiary is possible in Traveller, though it would be fun to have some "popular pets of the Spinward Marches" article.
Mongoose's Animal Encounters does have a set of 'templates' for adapting an animal to various UWP stats.
Unfortunately, the majority of the book is just the same random table with these templates applied to them. (To be fair, I've only examined a dozen or so tables, so it's possibly I just got incredibly unlucky.)
AE has a fantastically interesting system of generating and 'evolving' animals in its first few pages. I just wish they had used that system in the rest of the book. I know I've said this before, but I really feel like this is a combination of a few good S&P articles and a ton of tables with very little variation between them.
And of course the size|weight data is missing for all of the animals, as is the speed. No way to tell if you can outrun that hunter, or to judge how much meat that prey animal might net you in a survival situation (which comes up surprisingly often in old CT adventures...).
I guess I'm in with nats - I had high hopes for AE, and though the book shows a lot of creativity in some parts, the overall product is much less than it could have been.