A subtrope of Coat, Hat, Mask.
Basically any character that wears a gas mask and, well, a longcoat. Occasionally, there will be a good reason for this, like the character deals with cold weather and/or toxic fumes on a regular basis, but mostly these characters exist because it looks really cool. Trench Coats seem to be the preferred apparel, though other kinds of long coats are acceptable.
Often [...] [tvtropes.org]