Sludge was originally a siamese twin (not with Slash Vohaul, his good natured brother, but Slouch Vohaul) . During Sludge's childhood, he undertook surgery to get separated from his twin brother. Sadly, his brother got all the good organs and Sludge was sold off to research by his parents. He has not lived peacefully with this knowledge. Kinda put him in a full time pissy mood.