From the last Fall Out Boy single before their undefined hiatus, Alpha Dog. It goes with the word "megalomaniac," which is basically thinking your the shit, with the o added on the front so it looks like "omega" (To go with Alpha Dog). It's actually quite a good song.
Often spammed in twitch chat when the word transparent, doc, wife, cheating, etc. is mentioned in twitch chat. Makes fun of the fact dr. disrespect cheated on his wife.
An emote used on Twitch.TV Can only be accessed by using the browser addon BetterTwitchTV.
Used in a comical or funny scenario, and is an enlarged version of another emote by the name of 'LUL'.
random guy: my dong is long.
omegalong dong user: Why don't you use omegalong dong instead?
random guy: that's brilliant, i go and eat an omegalong dong sandwitch.