Foo Fu

"Just the fact that they can release a fighting game starring Shaquille O'Neal and call it Shaq Fu pretty much proves that you can put 'Fu' at the end of anything. How about Robin Williams Fu, or U2 Fu?"

—The Angry Video Game Nerd

As You Know, "Kung fu" (Chinese: 功夫, literally "achievement through sustained effort") is a collective term for a number of fighting styles which have roots as ancient as the 18th century BCE and have continued to evolve to this day. The greatest spike in popularity and variety of Kung Fu came in the 20th century; not only did the now-iconic "drunken boxing", "five animals" and "tai chi chuan" styles develop during that period, but upon exposure to contemporary western pop culture, Kung Fu experienced a veritable explosion of applications to a variety of professions, aspirations and walks of life other than the canonical kung.

Evidently, there was something exotic and evocative about the phrase Kung Fu and the excellence it symbolized that western culture found irresistible. Soon those privy to the great secrets of juggling liabilities and equity professed to be practicing the art of account fu, green-thumb enthusiasts the world over discovered the inner focus allowing them to transform their mere gardening skills into snip fu and high-brow enthusiasts began polishing their assorted gambits and defenses into bona fide chess fu.

Skills that were previously thought to be mundane were revealed to be awesome beyond imagination, with those graceful enough in their application often finding time speeding up and slowing down in the appropriate dramatic fashion as they snip a particularly difficult bonsai tree, perform en passant or locate the source of the $0.03 imbalance.

The term "Foo Fu" for this general phenomenon was coined Just for Pun, and basically means the same as "X Fu" or "Whatever Fu". It comes from "Foo", a placeholder often used by programmers as a stand-in for whatever should be there instead (the technical term for this kind of placeholder is "Metasyntactic Variable").

Trope Fu was originally considered as a name for this trope, but it was ultimately decided that Trope Fu is the sublime art of tending to examples and descriptions which we all practice in This Very Wiki.

Not to be confused with Frou Frou. Or Little Bunny Foo Foo.

Behold! A Flawless Demonstration of Index Fu

This is no mere section. This is Example Fu of the highest caliber

Anime and Manga

From Ranma ½: although the correct translation for the "Neko-ken" Dangerous Forbidden Technique is "Cat Fist", it is also often called "Cat Fu", especially in fanfictions. The prevalence of refering to it as "Cat Fu" in fanfiction might be because Genma refers to the technique as "Cat Fu" when he first mentions it in the English dubbed anime, going on to explain that "Cat Fu" is actually the shorthand reference for "Freestyle Cat Fist Fighting".

Comic Books

In Captain Carrot and His Amazing Zoo Crew, Alley-Kat-Abra knows Kat-Fu in addition to magic.

Film

Howard the Duck: "No-one laughs at a master of Quack Fu!"
Joe Bob Briggs' "Drive In Reviews" would often use the "fu" suffix when listing the various weapons used in the target movie, which would lead to line items like "hubcap-fu", "tree branch-fu" and "brick-fu".

Literature

The Discworld novel Thief of Time has "Déjà Fu", the martial art practiced by the History Monks, in which the practitioner travel in time as well as in space. The book give us as a translation: "The feeling that you have been kicked in the head this way before." Lu-Tze mentions that none of the monks know it. However, Lu-Tze is not a monk.
In her book about her life with Jim Morrison, the writer Patricia Kennealy refers a lot to "evil fu"...

Live-Action TV

Willow's Witch Fu is admired in an episode of Buffy the Vampire Slayer.

Music

The Brazilian band Pato Fu, whose name means — really! - Duck Fu.

New Media

This trope was inspired by a mention of "poor search-fu" in another entry, and hacker culture applies it to coding.
Google-fu is skill at finding the right keywords to use in a search engine. It's fairly widely used. It can be either good or bad, as in

"How did you find that so fast? I've been looking for it for days!"
"My Google-fu is strong!"

or

"Can someone with better Google-fu than me find a site for this?"

- Improve your Google-fu!
The GNU Image Manipulation Program has a Script-Fu console for making your own custom effects.

Tabletop Games

Card Games

The Munchkin card game has a set named "Munchkin Fu" (including a style card literally called "Wire Fu").
- The various style cards also all end in "fu". Banana Fu, Clown Fu, Gun Fu, etc.

Tabletop RPG

Cyberpunk has "Gun-Fu", the fine art of running up to people and shooting them.
The Exalted fandom coined the term "Social-Fu" to describe the Mind Control and More Than Mind Control effects Exalted can have on mortals, and possibly other incautious Exalted.

Video Games

Shaq Fu, a martial arts Fighting Game starring Shaquille O'Neal.
In Quest for Glory IV, the Adventurers' Guild bookshelf had a book on Talk Fu, the art of delivering witty One Liners during combat.
Dealt in Lead: The title earned by maxing your level in the hand-to-hand skill? Pencil-Fu. Yes, pencils can be used as weapons. Yes, it's awesome.
I-Mockery's Santa Fu.

Web Comics

Schlock Mercenary
- A variation when Schlock refers to the company lawyer as having "owned you with his legal-jitsu." Jitsu means art, so it actually is kind of appropriate.
- Played straight with the same character here: "Shodan told me you passed his unarmed combat course".
Inverted in one chapter of Footloose: the Combat Stilettos style is called... Kung-Shoe.
The webcomic What the Fu.
Strip #297 of Apple Geeks is titled "FlashFu". With good reason—it must be on the level of a martial art if you have it working on a woman.

Web Original

The Cheerleaders, a trio of supervillains from the Global Guardians PBEM Universe, regularly use their "Jiggle Fu" distraction powers against male opponents.
The Nostalgia Critic, about the aforementioned "Quack Fu" in Howard the Duck:

"Well, the superior joke here would be Tai Quack Do..."

Images-Googling for "Cat Fu" can get you some hilarious results.

Western Animation

The Flash cartoon Skunk Fu!
Darkwing Duck and his master Goose Lee are "Quack Fu" martial artists.
Although it may looks like it at first glance, Wakfu isn't an example of this trope. Its MMORPG spinoff The Guardians, however, features the "Wakfung" Supernatural Martial Arts.
Yin Yang Yo has the art of Woo Foo.
A martial arts themed segment of the Super Mario Bros Super Show has a scene in which Mario and Luigi try to learn karate and fail miserably... so the martial arts master trying to train them makes up a plumbing-themed martial art called "Plumb Fu", which they master immediately.

Real Life

The Marine Corps Martial Arts Program or MCMAP, also affectionately referred to as "Semper Fu". A play on the motto of the U.S. Marine Corps Semper Fidelis, which is shortened to Semper Fi.