Liam is the son of Heinz Doofenshmirtz, but not featured in the episodes since he was in school at the time because he is 11 years old.
He likes being evil and always follows his dads inventions so concidentlly, he knows Phineas and Ferb. But that also means Liam is the only one that knows his dads inventions always make Phineas and Ferbs inventions disappear.
He would tell them, but that might lead to his dad being arrested and he would'nt want that to happen, would he?
Liam likes Perry but, like Doofensmirtz, dosent know that he is Perry the Platapus. In fact even when Phineas tells him that the platapus is called Perry he still dosent figure it out.
Liam himself has made a few little inventions and whenever he can he helps his dad with his inators (eg. getting parts or screwing in bolts).
- Phineas - Good friends
- Ferb - Great friends
- Isabella - Ok friends
- Buford - Bad friends
- Candace - Ok friends
- Jeremy - Ok friends
- Vanessa - Good friends
- Guy from across the street - Good friends
- Girl from across the street - Bad friends
- Perry - Great friends (He likes mammals)
- Agent P(really Perry but he doens't know it) - Enemy
- Dill - Ok friends
- Jacob Greenfish - Best friend!
- Ian Makapook - Good Friends
- Emily - Ok friends
Liam: *Gasp* Phineas and Ferb's platypus!?
~Hat drops on perry~
Liam: PERRY the Phineas and Ferb's platypus!? Oh wait, that dosent make sense.
Doof: So have you seen Vanessa? I hope she's not with broccili head again.
Liam: He's called Ferb. And he is actually in a spaceship to fight mitch who has a word translator and if he dosent wear it he says 'meap' and meap dosent have a real name and Phineas made a cute translator and it blows up when Isaballa stands near it.
Liam: No. I just made that up.
Liam: Sooooo Ferb. How much do you weigh? And why is one of your eye's bigger than the other?
Vanessa: Why are you talking to a stop sign?
Liam: Ferb looks like a stop sign.
Liam: People dont apreciate you much.
Ferb: Oh but they will, THEY WILL! HAHAHAHAHAHAHAHAHAHHAHAHAHAAAA!
Vanessa: Why are you talking to a movie about an evil dark lord?
Liam: Ferb looks like an evil dark lord.
Liam: No, but it's fun imagining him in the body of an evil dark lord.
Liam: No. It's boring.
????: Why are you talking to a ____?
Liam: Ferb looks like a(n) ____.