Bootleg Spongebob is a version of Spongebob who originates from the creepypasta "Spongebob Bootleg Episode". He is the Opponent of a free play song in mistful crimson morning called dumped.

The image in which bootleg Spongebob appears in comes from a split second frame of a corrupted bootleg of the Spongebob episode "Dumped". The rest of the corrupted episode consists of random, incomprehensible jumbles of colors, static, or just black screens. The audio seems to be an extremely distorted version of the original episodes audio, accompanied with loud, droning buzzes interrupting it. The tape itself was found in December of 2004, when a group of 5 teenagers began rummaging through a trash can found within an abandoned mental institution. Of these 5 teenagers, 2 have committed suicide, 1 has gone missing(found dead inside of a dustbin one year after the discovery of the tape, 1 refuses to comment on the tape, and the last one hastily agreed to give to the paranormal investigators the tape shortly after being interviewed what happened to the other 3. As of now, the tape has gone missing, nowhere to be found, and many who stare at the Spongebob image for long enough claim to see him blink.

More facts here: https://fridaynightfunking.fandom.com/wiki/Mistful_Crimson_Morning#Bootleg_SpongeBob