Phineas and Ferb was a beloved kids' cartoon that ran on Disney Channel from 2007 to 2015. The show followed the two titular stepbrothers over the course of one (seemingly endless) summer, as they spent each day inventing some crazy new source of entertainment for their backyard pals. At the same time, their pet platypus which is a secret agent animal named Perry, would battle the evil scientist Dr. Doofenshmirtz as he tried different plots to take over the tri-state area.
The show was an instant hit, largely owing to the original storylines and novel humor of creators Dan Povermire and Jeff "Swampy" Marsh. It was one of the few shows at the time with enough heart and creativity to successfully grow its fanbase.
One of the noteworthy things about Phineas and Ferb was the nature of their blended family, which consists on one side of Phineas Flynn, his teenage sister Candace, and their mother Linda; and on the other side of Ferb Fletcher and his father Lawrence. The family is very happy and there's never any conflict related to the parents' marriage - in fact, they're shown to be a very sweet couple and incredibly loving, caring parents to all of the children.
However, as fans have grown, and as more clues about the characters' pasts were revealed, fans have started to ask questions about the parentage of the younger characters: Specifically, who Phineas' biological dad is... could it be Dr. Doofenshmirtz?
On the outside, this might just seem like another crazy, out-of-left-field internet fan theory, but some of the evidence presented is actually kind of convincing.
First Off, The Similarities Are Uncanny
Of all the characters in the series, there are only two who have heads that are triangular in shape: Phineas Flynn and Heinz Doofenshmirtz. While it's true that the features that produce the triangular shape don't quite line up, it's worth it to consider that this is animation — the general shapes probably mean more than anything else.
Doof and Phineas also have the same tiny tuft of hair on the top of their rather pointy heads. All in all, they do look kind of similar.
But looks aren't where the similarities end. The biggest commonality these two characters have isn't their strangely-shaped craniums or small hair: it's their penchant for invention.
The entire plot of the series revolves around the fact that Phineas and his could-be dad are the two most talented and disruptive inventors in town.
Dr. Doofenshmirtz is an evil genius who may never get a win with his inators, but that doesn't mean that the inventions themselves aren't impressive — and Phineas is the ideas guy: Ferb is smart enough to help out, but between the two of them, it's always Phineas coming up with the blueprints and spearheading whatever crazy project they have going on. (It's even implied in the few time travel episodes they do that Phineas will be the one to end up in an engineering career, while Ferb will end up in politics.)
Inventing talent like that could just be a coincidence...but the fact that the both of them are from the same town, and have such an advanced talent for it, suggests otherwise... especially when coupled with the fact that Heinz and Linda actually dated for a period of time.
The Timeline Is Messy, But The Connections Are There
Originally, the theory that Linda and Doof were an item was easy to debunk, especially given that in the very episode where it was mentioned that they were dating, Doofenschmirtz says that he never saw her again - and that was in the eighties. Phineas (if you assume that he was 10 and that the show is set in the year it premiered) was born in 1997.
However, fans online were quick to point out that it's very possible that Linda didn't have a traditional family before settling down with Lawrence when the boys were very young. The show has pictured them as a family when they're around preschool age, so presumably before they were both four. Before that, though, it's more than likely that Linda was always a single mother.
First of all, both Candace and Phineas have the same last name as their mother, which is uncommon unless the mother was unmarried when the child was born. It's one thing to change your own name when you get divorced, but it's a somewhat extreme measure to change your children's names too. And since Candace is six years older than Phineas, it's very unlikely that the two had the same father.
Second, shortly after her date with Doof, Linda underwent a transformation of sorts, and became the 80's pop star Lindana. Being a pop star on the road and living that lifestyle, it's very possible that both of her children were the result of one-night stands or short little flings. It would also explain why Heinz wouldn't have recognized her as the same girl he went out with years ago (especially because the 90's was when Lindana went through the "grunge phase" that killed her music career).
The timing works out for Doofenshmirtz as well. There's no way he could have been Candace's father: He was married at the time, as evidenced by the fact that his daughter Vanessa is the same age as Candace. However, by the time Phineas was born, he was more than likely divorced.
Is this fan theory a bit of a stretch? Yes. Yes it is. Plenty of fans have come up with reasons why it can't be true, and it causes a lot of tension in the fandom itself. But is it just crazy enough to be plausible? Maybe.
