Sue Sylvester (Glee)
Highly interested in having human slaves, and quickly becoming a media mogul at her local news affiliate in order to influence and confuse the opinions of the humans in her area. I don't recall if she's given her feelings on scientists as of yet, but considering she'd rather her Cheerios suffer a lifetime of illiteracy and general ignorance than lose a competition, she's probably not big on people who think for a living.

Ryan Seacrest (Every Media Property, Ever)
He doesn't seem to age, likely due to his technologically advanced human suit, he has those sharp little reptilian teeth, and as we know he has already conquered the entire earthly media. He's probably their leader.

Lo (The Hills)
I can't tell what that girl is thinking -- ever. This could mean one of two things: either she has no thoughts (admittedly possible), or she's evil and only on that show to systematically implement a plan to harvest Speidi for mid-afternoon snacks on her home lizard planet. I would be fine with either outcome, but if anyone is going to roast and eat Speidi it should probably be us. I think we've earned it.

The Observer (Fringe)
I usually lean toward robot or mutant on what exactly this guy is, but now I'm of the mind that he's bald due to being an extremely warm-blooded space lizard in a bargain-basement person costume. Less plausible plot twists have happened on that show.

Carter Baizen (Gossip Girl)
He's evil! No, he's a dreamboat! He's evil! No, he's a dreamboat! He does seem to be innately expert at manipulating everyone he meets with his charm and suspiciously classic good looks, and it's a well-known fact that all lizard people take their scotch neat.

Auggie (Melrose Place)
Auggie? Sounds pretty made up. And I don't know what anybody would want Riley for, but it's got to be something sinister, especially if you take his velociraptor-shaped head into consideration.

Padma Lakshmi (Top Chef)
Clearly, she's far too beautiful and serene to be human, and she very well could have been stationed on Top Chef to study the eating habits of humanoids in order to craft a flavor palate and new food pyramid for her planet's primary school students' new lunches (example: "Chili, chips 'n Fabio").

Foreman (House)
Foreman is definitely averse to all science professionals who are not himself, so he's suspect right there. And although it's never been an official storyline, someone who oozes unpleasantness so copiously has to have gotten Thirteen through mind control powers.

Dr. Sloan (Grey's Anatomy)
He's probably conducting human experiments for his lizard bosses on two different fronts. One, having sex with every female he encounters increases the possibilities of human/alien hybrid spawns, which is something the Vs dabble in, and two, he's a plastic surgeon, which means he could be doing an in-depth study on what humans find the most attractive, so upgrades can be made to the human suits. Because if all the Vs showed up here looking like the Observer, nobody would be lulled into colonization.

Dwight (The Real Housewives of Atlanta)
I know what you're thinking: why would the Vs send someone solely to infiltrate the South's amateur fashion shows and nail salons? So he would have the ear of influential celebrity Nene Leakes, that's why. You see, in the miniseries they recruited a prominent human mouthpiece to reinforce the Vs' message to the public, and I don't know about you, but if Nene Leakes told me our alien visitors were fine, upstanding folk I'd believe her, no questions asked. Nene speaks the truth (unless she's being mind controlled by galactic reptiles, of course).

Lizards I missed? Sound off below.