Originally Posted by FadeToBlack
But can somebody explain the trunk? I don't understand when does it talk?


The trunks make (very) infrequent (usually insulting) comments about things you do. It's like having your own private heckler.

Unfortunately, the trunks comments are only represented by very brief text that pops up above your character's head. Despite the location, it isn't voiced, and it isn't logged to the chat window, and is very easy to miss.