So a character wants to distinguish himself from the rest of the pack. Catch Phrases are always a good way, since you don't need to see them in order to know who they are. But a single catch phrase is so boring.
The answer: just add a specific prefix/suffix onto words.
In some cases, these characters will create new words with new meanings this way, but more often than not they're just the same word with that prefix/suffix tacked on, and no definition changes. Sometimes, also, other characters may start using these words as well, turning them into, in a manner, Borrowed Catchphrases or Share Phrases.
The ultimate of this trope is, unsurprisingly, McDonald's, who use their 'Mc' prefix on almost everything they sell. In their case, not only have their words made the general vernacular, but also their naming habits, as The Other Wiki has proved.
- In the Big Finish Doctor Who drama Spare Parts, generally regarded as the definitive Cybermen origin story, it's revealed that the name of the Cybermen comes from the Mondasian cultural practice of adding "man" as a suffix to any designation of a person, eg "Doctorman", "Sisterman", etc.
- Isaac Asimov and Janet Asimov's Norby and the Court Jester: The planet Izz has the Izzcapital, of Izzcontinent, has nationwide entertainment created at Izzbroadcasting. The royal family has a court of advisors, the Izzcouncil, that meet in the Izzhall. At the end of the novel, the royal family proposes to turn Izzcouncil into an Izzparliament.
- Doctor Who:
- The Cybermen are notorious and sometimes mocked for using "Cyber" as a prefix for absolutely everything they make or use in the style of Space "X", such as arming themselves with Cyberguns and Cyberbombs and travelling in a Cyberfleet.
- In "Utopia", we meet Chantho, an insectoid alien who begins her every sentence with "chan-" and ends it with "-tho". She can choose not to do it, but it's implied that it's her race's equivalent of swearing like a sailor.
- Grey's Anatomy gave some of its doctors nicknames starting with "Mc" (as well as a few parodic ones), most prominently McDreamy and McSteamy.
- Happy Days: Fonzie sometimes uses the suffix "-amundo" for emphasis: correctamundo, exactamundo, etc. When he was a Rogue Juror he even voted "not guiltyamundo."
- Kenan & Kel: Throughout most of the first season, and some of the second, Chris had the habit of adding an extra prefix to his preterites, usually a "be" or "buh" sound, such as:
"Kel, you be-bruised my bananas!"
"How could you buh-lose a lottery ticket?"
- Blaine of Project Runway season 5 liked to add "-licious" to words.
- Saturday Night Live: Adam Sandler's Opera Man from the early 1990s would sing his commentary in an exaggerated Italian accent by adding "a" or "o" to the end of many of his words. (An example (from Wikipedia): About the LA Riots - "La Chiefa Policia, no dispatcha gendarme/ morono, no respondo/ no excusa, bagga doucha!")
- Snoop Dogg attaches '-izzle' to a lot of his words, although a fair bit of those words have half of them removed, e.g. "fo' shizzle" for "for sure".
- In Dwarf Fortress forums, it's fairly common for players to refer to their dwarves as "Urist Mc(adjective or profession)". As in "Urist McMiner", "Urist McSpeardwarf", or "Urist McCannonfodder".
- Final Fantasy X-2: According to Rikku's brother, Brother, she has a habit of doing this with Spiran words, and even chides her for it. Most notably, her inclusion of "iffic" to the word "disaster"; resulting in "disasteriffic".
- The King of Fighters: Yuri Sakazaki has a habit of ending nearly all of her sentences, and certain words, with "-tchi". It was originally a schtick devised by her voice actress, Kaori Horie, which stuck and has since become a regular part of her character's speech pattern.
- In Captain N: The Game Master, Kid Icarus (who should have been named Pit) tended to tack "-icus" on the end of words.
- Due to the fact that he often speaks with a slight Speech Impediment (like that of a 5-year-old), Mr. Bogus will often use the word "mondo" before adding the letter 'o' at the end of a word used after it in his sentences: "Mondo coolo", "Mondo safe-o", etc.
- The Simpsons has two, by two different characters:
- Homeric ma-infixation is an interesting application of this in that the particle "-ma-" is an infix (it is put in the middle of a word), producing words like saxomaphone and babamabushka. Homer, as you can guess, uses it a lot.
- Ned Flanders also adds "-diddly" to a few of his words.
- Total Drama Season 4: Revenge of the Island had Lightning, whose big thing was words starting with "Sha-" (including Shazam).
- Similar to the Homer Simpson example, Yogi Bear frequently calls picnic baskets "pic-a-nic baskets".
- McDonald's is the Trope Codifier for this, with their menu of 'Mc' foods. Soon everyone started doing it, although it is seldom a compliment (e.g. 'McMansion' for a cheaply-made, soul-crushingly uniform house).
- Moscow on the Hudson character Vladimir does this when he works at McDonald's, to the point of making the parting statement to some customers, "Come back McSoon."
- Apple Computer's habit of putting an "i" in front of every new product is parodied enough to be its own trope.