Horny Scientist

Whenever a female protagonist has to consult with or bring in an expert on some obscure and/or technical subject, said expert will invariably turn out to be socially awkward and generally unattractive, but clearly smitten with her. A Horny Scientist is not, as a rule, sexually aggressive, and may in fact turn out to be strangely endearing in his own geeky way, but rarely actually becomes even a Temporary Love Interest.

Note, if this is a horny Mad Scientist, expect their creations to be somewhat... Freudian at the very least.

In contrast, a male protagonist will get a Hot Scientist.

Anime and Manga

 * Cowboy Bebop The Movie has one, who makes Elektra agree to go on a date with him in exchange for testing her blood for the MacGuffin.
 * A female example appears in the Defense Devil-manga, who never stop flirting and showing off in very Stripperiffic outfits whenever the male protagonist comes to her for help.
 * There are two in the Black Order's Asian Branch in D.Gray-man: Director Bak Chang, who has the hots for Lenalee and stalks her, and minor character Rohfa, who is quite infatuated with Allen.
 * Shinra Kishitani from Durarara. Unlike most examples, Celty actually has to live with him and he wishes that it would stop being just Innocent Cohabitation (having gotten a crush on her since he was 4, long story). At the very least there's some mutual feelings between them (although she's very tsun tsun about it) and he's by miles more attractive than the usual example.
 * Naruto: Shiho, the cryptographer with an instant crush on Shikamaru counts more as this trope than Hot Scientist, though she is kind of adorable in a mousy, nerdy way.

Film

 * Agent J in Men in Black mistook a medical examiner for a horny scientist when she was actually nervous (and trying to clue him in on an alien hiding under the table, which he took as double entendres).
 * Subverted in the first Charlie's Angels film. The socially inept Horny Scientist Sam Rockwell smitten with Dylan Sanders

Literature

 * In Silence of the Lambs, Clarice Starling has to deal with two of them at once - and, if you believe the book and the last few scenes of the movie, ends up dating one of them.
 * In City Of The Dead one of the Doctors (whose name escapes me) Has sex with zombies.
 * He's not really an assistant, though, so it might not count.
 * Kate Daniels has to deal with Saiman's efforts to bed her whenever she needs his assistance.

Live Action TV
"Rocky: You know, when a male and female calliphorid fly mate they stay joined for up to one and a half hours. One and a half, doctor. Scully: You know, Rocky ... I'm a mother. Rocky: Mothers are women, too."
 * In several episodes of Stargate SG-1, Samantha Carter deals with the irritating, Horny Scientist Rodney McKay (who was popular enough with audience and the writers that he became a main character on Stargate Atlantis). Rodney appears to have the hots for Colonel Carter, considering that he styled his country's ruler in "The Game" on her.
 * One wonders if this is to be swept under the rug now that the McKeller 'ship has set sail...
 * And then there was Dr. Felger, who not only had a crush on Sam, but idolized SG-1 to the point that he would risk his life to try to impress them by "saving" them after SG-1 was captured by a minor System Lord.
 * Tru Calling used a Horny Scientist as a main character (in fact, it seems a large percentage of them are medical examiners or pathologists, which may or may not add a layer of Squick once the Fridge Logic kicks in).
 * Scully on The X-Files had two of these, Agent Pendrell and Frohike of the Lone Gunmen.
 * Frohike, while fitting this trope in the first couple of seasons, continued hitting on Scully afterwards because he found it amusing. See "Three of a Kind."
 * And let's not forget Rocky the entimologist from "Lord of the Flies", who is so smitten with Scully that it leads to this lovely conversation:


 * Richard Sanders made a guest appearance on Designing Women as a scientist with the hots for Charlene.
 * Murphy Brown went out with a brilliant physicist she had interviewed. She expected a quiet evening of stimulating conversation, but found herself accosted by an obnoxious, lecherous Casanova Wannabe.
 * An expert consulted in several sketches of Royal Canadian Air Farce is Professor Ick, an unattractive and horny female scientist. She constantly flirts with the interviewers and her explanations always become sexual, usually with pelvic thrusts and moans. She sometimes has a male colleague, who tends to act the same way.

Video Games

 * One of the possible team acquisitions in the RPG game Fallout 2 is scientist Myron. He is definitely horny. And sleazy.

Web Comics

 * Despite no one ever needing to consult with him, Tedd from El Goonish Shive is clearly a Horny Scientist, albeit a successful one - Dr. Germahn from the Q&A strips is also this, doing stuff like creating potions that will make sweat dissolve clothes.
 * Dr. Schlock of Sluggy Freelance can be quite the perv. Strangely, even though his specialty is inflatable technology, we've never seen him ... let's say, combine work and play.
 * Given his lack of skill with genetics, he presumably succeeded at some point, since
 * Dr. Disaster from Gunnerkrigg Court

Western Animation

 * Douglas and Adam from Foster's Home for Imaginary Friends, perhaps in a Shout-Out to most of the male fans of the show.
 * Female example: DNAmy from Kim Possible.
 * Sheldon of My Life as a Teenage Robot loves Jenny. LOVES her.

Comic Books

 * Gina Diggers from 'Gold Digger' is very much an embodiment of this trope. Her libido has calmed down a bit over time, but she and her clone half sister Brianna both have plenty of moments that highlight just how huge their Libido's are.