One popular snail joke is: A snail walks into a car dealership and asks for the car to be painted with a big letter "S". When the salesperson asks him why, he replies, "So when people see me, they'll say, 'Look at that S car go!'"
The joke is funny because "escargot", pronounced "ess-car-go", is the French word for snail and is a well-known delicacy closely associated with French cuisine. Another well-known snail joke is: "What's the difference between a snail and a politician?" "One is a disgusting pest that leaves a slimy trail everywhere it goes, and the other one is a snail." Snail jokes also often make reference to the snail's reputation for slowness.