Guidestuck is the first MS Paint Adventure written by scarvenrot, and currently the most popular of its kind. It is an alternate universe of Homestuck, in which four non-human characters - namely John's harlequin doll, Rose's cat Jaspers, Dave's puppet Lil' Cal and Jade's dog Becquerel - become human characters Quinn Egbert, Jaspers Lalonde, Cal Strider and Becquerel Harley. Likewise, John, Rose, Dave and Jade are dehumanized.
Like in Homestuck, the main plot of Guidestuck revolves around Sburb Omega. Their session is repeatedly stated to be failed, both in-universe and by the author, but the main characters are oblivious to it.