So, using the help of Google and some 45 minutes of research, I found that what you are looking for might be called an egg corn (eggcorn).
An egg corn or eggcorn is when you deliberately make a pun with an intended malapropism (all definitions will be at end of answer).
Lord of the Fries
Lord of the Fries is the name of a chips (or fries for you Americans out there) shop, with a name being based off of "Lord of the Flies".
By changing "flies" to "fries", they are making a malapropism, albeit it being intended.
Another example of this is (while continuing with the fish and chips theme):
This fish shop's name is a pun on the film "The Godfather".
Other examples are "Wok 'n' roll", "Pita Pan", and "Sew What?", being respectively similar to "Rock 'n' roll", "Peter Pan", and "So what?".
A pun is a word or phrase with usually two meanings, although it can be more. Puns are intended to be funny.
An egg corn (eggcorn) on the other hand, is a pun with an intended malapropism, yet it is not intended to be funny. Essentially, it just "happens".
A malapropism is when you incorrectly substitute a word in, which has a similar sound, yet entirely different meanings. A Freudian slip seems to have a similar meaning.
And that should be it. I hope this was of at least some help to answering your question.