Mickey
A mysterious drifter, he 'happened' upon Dean
Winchester after the brothers left Senator
McKendrick.  He's not very forthcoming about
himself, calling himself Mickey, no last name.  But
giving him the last name 'mouse' is not only not
funny to him, it is also completely against who he is.

He's self assured, with wise eyes.  Strongly built, and
the hint of an Australian accent, though he claims
he's never been there.  There are a few scars he
doesn't care to explain, and a knowledge of warfare
and weapons that he refuses to tell where it came
from.

He demands answers, but gives none.  Just saying
he's 'here' on an 'assignment'.  That's it.  No further
explanation given or offered. And getting that out of
him hadn't been easy.

And when the truth is revealed, if it ever is, he is
sure the people around him won't be prepared for it.
There are only certain things mankind can
comprehend after all.

He imagines he'll be amused by the reaction
of Dean and Sam when they learn the truth.

That he is responsible for their father's
resurrection.

That he had walked into the depths of hell to
retrieve John.

That his mission is quite simple.  Train the
champion so that he may defeat the evil that is
coming over the world once again.

He cannot do it himself, for even archangels
are governed by rules and limits.