Stockholm

Stockholm is the sentry guard of Megaton. He is watching the surrounding area for enemies from a catwalk around the Megaton gates.

Stockholm however, is not reachable so interaction with the man is not possible. However, should you be attacked by a creature, that creature, if in it's range, will be taken out by Stockholm and his Sniper Rifle. For as far as I've seen, he's a decent shot.

Appearances
Stockholm appears only in Fallout 3