Here’s another meme (like Over 9000) that started with a Dragonball Z character - Cell is one of the main villains in Dragonball Z (specifically 'Imperfect Cell').
Someone on 4chan’s /b/ board used the very basic paint program, MS Paint, to alter Cell’s face into what is now known as Shoop da Whoop.
Cell's face has been blacked out and big eyes and red lips have been painted in amateurishly. A picture of ‘Shoop’ is usually accompanied by a phrase like 'IMMA CHARGIN MAH LAZER’
But Shoop da Whoop has a dark side – apparently, the Shoop da Whoop character was intended as a parody of early comics and thetre shows that featured black people in a stereotypical way, with bright red lips and very dark faces. (Like the 'Blackface' theatre characters seen on the American stage in the 1830's.) Even the ‘Shoop da Whoop’ wording and the phrases ‘IMMA CHARGIN MAH LAZER’ or ‘FIRIN’ MAH LAZER’ are meant to imply a typical African-American Southern drawl. The 'Imperfect' Cell character and another Dragon Ball Z character called Mr. Popo both caused some controversy for their resemblance to 'Blackface characters.
Pictures of the Shoop character generally appear in succession. Shoop usually starts by charging his laser, then shooting it out his mouth, then swallowing it.
Since the meme's introduction, numerous spinoff images have also been created, featuring various characters painted with the Shoop face. Check out many YouTube videos featuring Shoop.
Here's a YouTube video, featuring the 'Firing my laser' phenomenon.