"Nobody messes with Adam Williams!"
Adam is the Step-Cousin of Phineas, Isabella & Candace and is Andrew & Tara's biological uncle.
Adam was born in 1998 and was the son of Steve & Beth Williams and the brother of Eric, Mandy, Thaddeus, Thor and Nick Williams. And his stepparents are Danny and Bridgette Oshinomi. When he was 3, Adam was abused by Nick and Eric got badly injured and Nick was arrested later on. After that, Adam began to have nightmares about Nick and suffered PTSD. Thankfully, Adam met his Step-Cousins Phineas & Isabella when he was at the same age & they started building inventions together, ending his nightmares.
Steve & Beth was surprised to know Adam is now interested in Engineering and inventions and even his Uncle Robert. Robert told Adam that one day, he will be a inventor and also tells him he will always do well. Adam then met Candace & Ferb (Who thought was his step-cousin) after that. Steve was thought killed in the hit and run when Adam was 6, but actually faked his death to get away from Mark. Andrew & Tara got taken away from Adam when he was at the same age by their father Nick. Adam thought Andrew & Tara was murdered.
Adam met the Louds when he was 7 and even rescued Lincoln & Luna from the bullies, starting their Brother-Brother & Sister relationship.
While Adam was at school, he met Cameron and the gang and became friends, but he also met Daniel and he didn't like him, which starts their rivalry. He also met Ashley and married her. When Adam was 10, his Uncle Robert died of illness. Before Robert died, he told Adam to be strong and be a good inventor. Mandy left the family when Adam was 11 and didn't see her since. At the same age, Adam joined the Danville Police Department, which made his parents, his siblings and other relatives and friends very proud of Adam.
Adam then parted ways with the Louds, but then made a promise to Lincoln & Luna that he'll return someday.
Adam met his pen pal Ivan when he was 14 and they became good friends.
Adam is kind, sensitive, funny & very handsome and he never lies, although in "Ivan & Adam's Lies", he sometimes does. He is also confident, strict and serious. Adam doesn't mind when everyone makes funny jokes and tease him, but he doesn't like anyone making fun of him. He can get angry sometimes when a bully threatens his friends or family or anything else. He also gets scared of heights, bad dreams, spiders, and everything else.
Although Kind, sensitive, funny, strict, caring, and compassionate, Adam can sometimes be short-tempered, or in other words, high-strung, getting frustrated easily, and shouting when angry.
In The New Adventures of My Little Pony: Friendship is Magic, Adam has the same personality.
His main outfit is a light blue shirt, orange skinny jeans and red and white sneakers.
Adam's swimsuit consists of an green pair of swimming trunks with red stripes.
For bedtime, his PJ's are striped light blue with darker blue stripes. He also sometimes wears his light blue bathrobe.
Like Phineas & Ferb, Adam is very good at building inventions and is sometimes the boss. Adam also designs the weapons and uses them for target practice and emergercies. He doesn't use his weapons often.
Phineas & Isabella are Adam's long time step cousins and they get along well with him. Phineas & Isabella took care of him since they met each other and Adam thought of them as a brother and sister.
He always builds inventions with them, but can be the boss sometimes. He also sometimes takes Candace's place to bust them. Phineas & Isabella likes Adam very much and thinks of him as a brother. Even though Phineas & Isabella likes Adam, they can sometimes argue sometimes.
Adam also knows about their relationship and calls them "lovebirds" or "Phinbella" and tease them about it, annoying them.
Candace, along with Phineas, Ferb & Isabella likes Adam very much and thinks of him as a brother. She was amazed that Adam was like her in the past when he busted Mandy when he was little.
Chris is Adam's son and Lola's brother. Adam is amazed that Chris wants to be like him one day.
In Phineas & Ferb: The End of My Little Pony Part 2, Adam was devestated to lose his friends, but he remembered that the elements of harmony can revive them, so Adam used it and it worked! After Phineas, Ferb & the gang & Twilight, Spike, Applejack, Rarity, Rainbow Dash, Pinkie Pie & Fluttershy defeated Mark and his daughters Jasmine and Annabelle, they have a celebration party and Adam is awarded a hero medal, but Adam gives Twilight & Spike a special award which is a special bracelet that gives Twilight & Spike an ability to use ultimate magic. Twilight & Spike are pleased with their gifts, including Adam's speech. They embrace Adam in a hug before saying goodbye to him.
In Cupcakes parts 1 & 2, Adam & Applejack, Rarity, Rainbow Dash, Pinkie Pie and Fluttershy hears that Phineas, Isabella, Twilight & Spike is at Mark's Evil Incorporated for a "special party", but Applejack, Rarity, Rainbow Dash, Pinkie Pie and Fluttershy gets knocked out by sleeping gas and is taken to Mark & his Minion's cellar to be interrogated on why they decided to have a party with humans, along with Phineas, Isabella, Twilight & Spike. Adam manages to get to Mark & his Minion's cellar and save Phineas, Isabella, Twilight, Spike, Applejack, Rarity, Rainbow Dash, Pinkie Pie and Fluttershy, but when he sees Mark about to shoot Twilight, Spike, Rarity, Stacy, Phineas & Isabella and not wanting to lose them, Adam saves their lives, but he gets shot and put in a coma.
- Main article: [[Adam Williams]]