The Sword and Laser discussion

Ruth wrote: "It would be too painful if something bad happened."

Agreed. If I could only choose one animal though, I'd go with something like a bowhead whale. Whenever I'm stressed out, I could just take in his relaxing, underwater surroundings. Plus, they live 150+ years.

After reading book 3 - I think Ferret.

Something with opposable thumbs like a chimp Would be much handier for carrying out useful tasks..and of course weapon training :)

No creepy crawlies? No one wants a big poisonous spider - a great companion for an assassin, right? :P

What about bees? Terry Pratchett's bees are one big creature, the hive, made of all the bees in it.

I'd go full on Granny Weatherwax and bond to a ... bee

I like a lot of the suggestions, a ferret or a rat for portability, I like both animals or maybe a dog, their so loyal and will defend you if need be.