The pink fish is a graphical meme within the Doom community. The fish originated with Dave "mewse" Kiddell, who first used it as an avatar on the Doomworld forums. He supposedly found the picture of a fish on a website, although the website itself is unknown. According to him, "Teenage boys generally choose avatars that are drenched in blood and suggest satanism. In order to buck the trend i think i searched for 'cute anime pictures'". The fish avatar quickly spread to other people, some of whom created modified versions, such as a green fish, an upside-down fish, and so on.
Mike "Cyb" Watson later created a series of AVI movies entitled "The fish show". This featured four fish derived from the original pink fish image. The fish communicated by saying the word "booyaka!", based on a cartoon imitation of Derek "Afterglow" MacDonald saying the word.
The pink fish is sometimes confused with the dopefish, although the two are not related.