Slop-Vipers are culled from the ranks of the Toxo-Vipers because the Cobra mess halls often resemble a bio-hazard. They wake up at 0300 to begin preparing, cooking, and serving breakfast for the Cobra legions. Afterwards they get to swallow down a bite for themselves before cleaning up and starting all over for lunch and again for dinner. Since the food is low quality, the service is completely lacking, and the conditions are just above unbearable, no body gets chewed out more then the Slop-Vipers. It isn't uncommon for Slop-Vipers to receive bribes for better food or simply for food that isn't spit in.
Medi-Viper #22, "I've seen Vipers heal very quickly from serious wounds just from thinking about months of eating chow from a Slop-Viper."