X-Stinky Agenda

Now, it goes without saying that we've been big X-MEN fans here ever since the 90's.

But one thing still puzzles & leaves us dumbfounded to this day.
This is the riddle of the "WHO THE HELL IS THAT GUY?" mystery.

I mean seriously,here HE is again.

Here's the actual video,

He has not appeared in a single EPISODE nor does the COMIC BOOKS ever mention about his existence.
Well that's pretty weird.

So our question is still this.
WHO THE HELL IS HE?
& why the hell does he get to run with all the big boys when he isn't even in any of the episodes.
You better come up with an appropriate answer now, MARVEL!

We'll be waiting!