Snail Milk is a type of milk that only appears in the episode "New Digs."
The milk is kept in a transparent glass cup, and the milk itself looks just like ordinary milk from the real world. It is from snails and it makes people fall asleep pretty much instantly and quicker. It is best served warm.
Role in episode
SpongeBob drank this to fall asleep faster in the episode "New Digs" after trying everything else in the book that he had read. Within the first few seconds of drinking it, nothing happened. However, after SpongeBob then screamed about how he couldn't go to sleep, the milk made him go right to sleep.