Tiffany Thompson

Tiffany Ivy Thompson is Isabella's long lost twin, as announced in Tiffany Moves to Danville. Isabella was born a few minutes before her, but Vivian and Tiffany's now deceased father, Benjamin, said they could only afford to care for one child, and gave Tiffany up for adoption. A nice family, the Thompsons, decided to adopt her, but she is still bitter to her real family.

Tiffany looks just like Isabella except her hair is cut shorter and she has green eyes. She wears clothes just like Isabella's just to mock her.

She thinks the world of Phineas and would jump off a building for him. They almost developed a husband and wife relationship until Phineas realized that she was a jerk.

She hates Isabella and whenever they come across each other, she crosses her eyes and says, "Hi, I'm Isabella! I'm stupid, worthless and unfashionable!" then gives her an evil smirk.

She treats Ferb like a brother and would do anything for him as well.

Teams up with him to torment Isabella. They are best friends.

Will bully him when she is with Buford, but secretly tells him that she wants to be friends with him.

Treats her like a sister. They are best friends because they are both jerks.

Says, "Eww! Phineas, you're my boyfriend, but I still think that thing is GROSS!"