What is the worst thing that can happen to you at camp green lake in Holes by Louis Sachar?

Depends on what you fear most. It could be being slashed by fingernails coated in rattlesnake venom... being bitten by a lizard with dire consequences, or having to run from the camp and die from dehydration and/or starvation depending on what you find. Also, having your name taken from the camp record so that your parents can't even find your body would kind of stink as well...