+1 for growing animals!

It would be nice if the pets would also level and get older. They could gain new abilities, like searching hidden places/treasures, or sensing danger, or 'summoning' other animals to help...
But I wouldn't make them too mighty. It would be boring to have a dragon, a companion, a henchman doing the dirty work...
But it would be also nice if there is something only to follow you, hiding during combat and come back later.
Will it be possible to talk to this pet? It would be good to write dialogues as well.