[Name] Mad Snail Disease [Source] SpongeBob SquarePants (Once Bitten) [Symptoms] 
A psychosomatic disease that is supposedly spread by an infected snail's bite. The imagined symptoms are as follows. In the first stage of the disease, after being bitten, toxins enter the body through the bloodstream, moving through the host until the host's body is taken over. Symptoms include: bloodshot eyes, messy pants, severely untrimmed toenails, ticklish ribcage, and loss of balance. After final stage, the host becomes a "zombie". In the episode "Once Bitten", Gary bites Squidward and most of the citizens of Bikini Bottom. Due to misinformation over the disease, they believe they are zombies and chase SpongeBob until Dr. Gil Gilliams, SDE, SE (Snail Disease Expert and Snail Expert) informs them that "Mad Snail Disease" is nothing more than an urban legend. It's name is a reference to prion diseases like Bovine spongiform encephalopathy and Creutzfeldt–Jakob disease. Infected snails show rabies like symptoms, including irritability, foaming at the mouth and aggression.