Mad Snail Disease



Mad Snail Disease is a mythological disease/virus that was believed that snails could be afflicted with. It appears in the SpongeBob SquarePants episode "Once Bitten" and the books Mistaken Identity and Attack of the Zombies!

In When the Cold Breeze Blows Away, it became a real disease/virus when the Undead Alliance bioengineered the MSD, but it was also later used by the South Vietnamese Umbrella Force.