Horrible Wiki
Johnny Snow
Johnny Snow
General Information
Affiliation(s): N/A
Other Information
Appears in: Dr. Horrible's Sing-Along Blog (Act I) (Mention), Comics
Songs Performed: None
Dr. Horrible, I see you are once again afraid to do battle to your nemesis. I waited at Dully Park for 45 minutes.

—Johnny Snow's email to Dr. Horrible

Johnny Snow is an ice-themed superhero who emails threateningly to Dr. Horrible, whom he thinks of as his nemesis. Horrible seems to suggest that Johnny Snow, who is never actually seen, arms himself with an ice beam and wears a parka (a reference to a DC comics villain Captain Cold).

Johnny Snow is referenced only twice; this occurs immediately before and during the Freeze Ray song.

He possibly alludes to a character from Buffy the Vampire Slayer who had a freeze ray and was named Jonathan Levinson.

http://www.imdb.com/title/tt0533486/ [1] [2] Johnny Snow might also refer to Jon Snow from George R.R. Martin's Song of Ice and Fire. 

There is actually a game where the main character wants to make it snow in San Fransisco. Johnny Moseley AKA Johnny "Snow"