Tam (the human) is 16, he is kind of shy, has a pretty bad anger management problem and sometime Dim has to knock him out to calm him down, he can hold grudges till you apologise or "vanish" and he's an Bisexual child.

Dim (the Dragon) is a separate being!! His species of dragon latches onto something and just stays there so that they are safe, he can detach if he wants but stays around Tam since they basically need each other to survive.

^Dim's full form

Here have a small sketch of 'em

Tam: Quit your whining you bread loaf

Dim: :c but tammmm you've been reading that for hours

Tam: your point?