Legion of doom is a team of super villains. They are owned by DC comics. Originally, they were in the very 70s Superfriends franchise. Villains are organized in a swamp. Creation of the legion of doom was considered the first villain group in non- comics media. 13 villains are there. Here are the names.

Bizarro- a retarded, but hilarious evil version of Superman.
Lex Luthor- you should know who he is.
Toyman- a creepy man who uses toys against victims.
Brainiac- smart alien (the opposite of George W Bush).
Riddler- played by Jim Carrey in a film.
Scarecrow- a grown man who dresses like a damn scarecrow.
Cheetah- Wonder Woman's arch enemy who has a spotty agenda.
Giganta- lady who has a huge vagina when using her power.
Gorilla Grodd- cheesy, but smart villain who has telepathic powers.
Captain Cold- a better version of Mr. Freeze due to the fact that he wasn't in Batman and Robin.
Solomon Grundy- zombie who wants some pants.
Sinestro- alien with a killer stache.
Black Manta- Louis Farrakhan type of guy who thinks only black people should have world control.

Overall, this is a dangerous group. Most likely, they are the most well known of DC comics supervillain groups. Read about them on the internet or watch youtube videos cuz this is a cool gang.