The Dragon Professor

But after all is said and done, the man believes that his hamster talks - that is a 5yo's child imagination level. To fall in love one has to be mentally older.

I'm basing everything I know about the realms as growing up as a longtime PC and DM of D&D 3rd Edition, but I was under the assumption Boo was Minsc's ranger animal companion, thus having an empathetic link to him allowing them to converse. Maybe not as simply as talking like humans do, but to a degree enough that they can get their points across. True that could just be the house rule I was raised with, but to me Druids and Rangers are meant to be able to converse with their chosen companions.

EDIT: Also, back in AD&D there was a campaign setting where "Giant Space Hamsters" existed, thus its not impossible for miniature breed of those to exist. The Planar Sphere of BG2:SoA has shown us that inter-dimensional travel is possible, to the point of a group of knights from the Dragonlance setting being present. Thus to me its quite possible that Boo is, in fact, a Miniature Giant Space Hamster and the chosen animal companion of a ranger named Minsc who can converse with him.

EDIT edit: Hah, I only just realized no one's touched this thread in six years.