Trogdor

ORIGIN:

Trogdor originates from the “Strong Bad” show on Homestar Runner. Originally, StrongBad was showing a viewer how to draw a dragon. After moderate popularity of the episode, Trogdor has become a popular in-joke among Strong Bad fans.

[information on when the episode aired would be appreciated: I can’t find it anywhere]

The original episode.

SPREAD ON THE INTERNET:

Trogdor has been placed in numerous image macros, often themed around destruction and “burnination” caused by Trogdor.

The creators of Homestar Runner and Strong Bad also created a Trogdor game.
Trogdor Game:
http://www.insane-games.com/games/trogdor/

IRL Popularity:
Trogdor’s theme song from the StrongBad episode was given a rock makeover and included in the video game Guitar Hero 2.