BE WARNED! MAJOR SPOILERS FOR ALL THREE SEASONS
Evil Queen/Regina Mills: Regina may be the evil queen in the classic story of Snow White, but she didn't start out that way. Regina was once a young woman desperate to escape the shadow of her mother. She was a kind, independent, and free spirited girl. She fell in love with her stable boy Daniel. One day while visiting Daniel during her "riding lesson" The evil queen is evil because snow white couldn't keep a secret about the evil queen. That they were running away to be together. Then Cora her mom ripped out her true loves heart. Then a little after that she got magic from Rumplestiltskin to banish her mom to Wonderland. Now the evil queen wants revenge on Cora and Snow White. So she learned how to rip out hearts from Rumplestiltskin. Regina cast a curse from Rumplestiltskin now all fairytale characters are in Storybrooke. Regina Mills is the mayor of Storybrooke she has a white mansion. Everyone is frozen in time there so she is bored there. One day she went to a adoption center to get a baby. She got a baby named henry she loved him a lot.
Rumplestiltskin/Mr. Gold: When Rumplestiltskin was a child his father abandoned him. A lot later he wanted to be in a war. But he did what he was not suppose to do he lifted a blanket off of a jail cart and met a seer. The seer said his actions on the battlefield will make his son fatherless. So he hurt himself with a jackhammer. So he could get home to his wife and son. He got back and met his son Baelfire but his wife knew he was being a coward. then his wife left him for captain Hook. He killed his wife to get revenge on her. To get revenge on Hook he cut off his hand. A lot later he got magic from a dagger then later he got a bean for him and his son to go to the real world but he was a coward. Mr.gold is the person who owns Storybrooke. He also owns a shop with a bunch of antiques from the enchanted forest.
Cora/Queen of Hearts: Cora was the daughter of a Miller. She wanted more than anything for the royalty who called her dirt, to kneel at her feet. So Cora, looking to make her dreams come true sneaks into a ball and was caught by the king. Feeling brave, Cora told the king that he was missing out on something amazing that could make his kingdom rich. She claimed she could turn straw into gold. He told her it was her duty and that she would spin the straw into gold or he would kill her. Rumplestiltskin appeared to her and taught that to spin she needed to think of her darkest desires. Overtime she developed feeling for Rumple and promised him his child. When she finally got her wish, she realized that the only way she could get her revenge was by ripping out her own heart. Cora later gave birth to Regina. Much later, the heartless (literally) Queen controlled her daughter and manipulated Snow White's life. She killed Queen Eva, spooked Snow's horse, killed her daughter's lover, and put Regina in the position to be Queen. Later she became The Queen of Hearts in Wonderland until Hook came to retrieve her for Regina. She protects her and Hook from Regina's curse and resumes her quest after Emma breaks the curse in Storybrooke. After determining the whereabouts of Snow and finding a way to Storybrooke she and Hook prepare a portal. Snow and company come and foil their plans. Though seemingly foiled, hook uses a dead bean and creates a portal. Once in Storybrooke Cora fakes the murder of Archie. Regina is framed and accused. After reuniting with her daughter she and Regina try to get the dark ones dagger. She dies in Regina's arms after being given her heart, cursed by Snow.
Peter Pan/Pied Piper: Peter Pan is the villain of the first part of season three. He lives in neverland with his lost boys. He is far from the mischevious good natured boy in the disney cartoon. OUAT's Peter is a boy feared by all. He enjoys playing mind games with the people who come to Neverland. Peter is actually the father of Rumplestiltskin. He was turned into a boy so that he could fly, however doing so comes with a price. Pan is being kept youthful but will eventually die. In order to stop his fate, Pan plans to take the heart of the truest believer who turns out to be Henry. This will render him immortal. Pan is stopped by Regina, but refuses to go down without a fight. While the crew of the Jolly Roger prepare to set sail for Storybrooke, he sneaks into the captain's quarters and attempts to take Henry's heart by force. He is unable to take Henry's heart due to a spell performed by Regina. Instead he tries to take Henry's shadow. In the process he switches bodies with Henry. He plays Henry for a time until he gets a hold of Regina's curse. He casts it to create "The New Neverland". Rumple finds a way to restore back to his body. The two have a talk and he renders Rumple powerless with a cuff. He goes off to kill Rumple's loved ones but is stopped the Dark One. He is stabbed with the Dark One's dagger and is reversed back to a middle aged man. He and Rumple disappear. It is assumed that he has died, but its not known for sure. The Pied Piper is a kid who guides children who feel lost to him.
Wicked Witch/Zelena: Zelena is Regina's sister who got given away because her mom was going to be queen instead. She heard about Regina and turned green with envy (literally). So she went to the wizard of Oz who is really a guy named Walsh. Walsh gives her magical shoes to make her teleport all she has to do is click her heels twice. Rumplestilskin trys to train her but he thinks regina is better. So now Zelena is trying to take her revenge on regina.