Here are the legends that used to exist in the USSR...
1. Metro. Doors are about to close. A civilized person - in a tie, indispensable detail - wants to get in, the doors are closing and his head is already in the subway car and stuck in the doors and the rest of the body is still on the platform. He looks sadly at those who are in and says in the fallen silence - "That's great! F*** underground!"
2. Kvass trailer tank. A kvass trailer tank turned over (usually in an accident) - and on its bottom were giant gentles (cestodes, another alternative - a corpse).
3. Foreigners - wreckers. They gave Soviet children sweets (or chewing gum) infected by tuberculosis or syphilis (alternative: farced with needles or pieces of razor blades, more exotic alternative: farced with baleen). Probably this legend was told by grannies for educational reasons in order children wouldn't take anything from strangers.
Instead of foreigners might be prisoners, they left bandages with tuberculosis phlegm in the playgrounds.
4. Foreigners sold black marketeers jeans infected by syphilis. The last ones sold them to unwitting fellow citizens. Usually on the back seam there was a package with flea (lice) scaring poor people at first jeans wash.
5. The story about some pioneers parade in Red Square. They said the pioneers were parading doing their best and vile foreigners were throwing provocative gum under their feet, allegedly to break their formation. No effect! Such consciousness!
6. Everybody died. A boy was playing with scissors and put out his own eyes. While terrified mom was running about the flat a girl sank in a bath. When mom saw it she jumped out of the window from the 10th floor. Dad was in no minute at home, saw a dead mom's body on the asphalt, a blind boy and a dead girl, shot the boy from a gun and shot himself too. Everybody died.
7. Food production know-how. Toilet paper in sausage, vodka made of petroleum (or sawdust). Bromine in soldiers' tea - to restrain them from chicks, diphenylhydramine in vodka (beer) - to make people drink less and crash out faster. Detergent in beer - for better froth.
8. Unusual findings in sausage or pasties - human fingers, teeth, rat's legs or tails.
9. Convicts built a helicopter from a gasoline-powered saw and escaped from a prison camp.
10. Radar vehicles driving about the streets and checking videocassette recorders concerning prohibited cassettes.
11. That's how they struggled with watching ideologically dissolute movies (like "Rembo", "9 1/2 weeks" etc.) - electricity was cut off and without electricity cassettes couldn't be taken out from the recorders. They went to a definite flat and evidenced that.
12. Underwater - underground USSR. Allegedly there existed huge underground plants where some cool and highly secret equipment was produced. There related the legends about tanks moving along the ocean bottom and underwater warehouses of atomic bombs in the Atlantic.
13. Rockets and large bore cannons covered with "fangs" on the bumper of KGB "Chaika" cars.
14. "Red film" that was loaded in a camera to photograph people. They were with clothes on, but looked nude in the film.
15. In a drugstore some scarce staff was given for a kilogram of dried mosquitoes. And some money - about 100 rubles.
16. Uranium mines - sentenced to death people were sent to U-mines and someone saw them later - toothless and sick.
17. Chinese carpets were glowing in the darkness with a silhouette of Mao Tse-tung lying in a coffin weaved with a special phosphoric thread, ... invisible in a daylight.
18. Loss of criminals playing cards. They lost seats in the movie theatre. A defeated one sat down behind the loser seat, and while viewing a movie, killed an unlucky spectator with an awl in his heart.
19. Muscovites affirmed that there was some phone number, let us assume 777-13-13, dialing which you could find yourself in a party mode, where everyone could speak with everyone...
20. Sailors who sailed to the west, and other lucky ones, could buy there ordinary cigarettes in ordinary packs (Marlboro, Camel...) but in the same packs it was possible to buy marijuana (marked with three black stars with a name "cigarettes with marijuana")! Someone brought them through customs and someone were treated here, at home.