What would you call someone who isn't afraid to ask for money or any kind of favor or who misinterprets someone's generosity for a consistent resource for what they need?
a person who habitually depends on the charity of others for food, shelter, etc.
We used the term "mooch" (def 7) when I was younger. I think that one literary offering is "takers" (Ayn Rand's Atlas Shrugged)
3 : a hanger-on who seeks advantage or gain
You could also call that person a sponge:
8. One who habitually depends on others for one's own maintenance.
The term sponger is also used to mean the same thing, chiefly in British English.
One meaning of the word parasite is:
One who habitually takes advantage of the generosity of others without making any useful return.
a person who borrows from or lives off others
Would you allow the Yiddish schnorrer?
“One who habitually takes advantage of others' generosity, often through an air of entitlement.”
Exploitative, as in 'tending to make use of selfishly or unethically'.
I'd agree with Dan; I'd call that person a mooch. From NOAD:
(verb) ask for or obtain (something) without paying for it
(noun) a beggar or scrounger
You can also use moocher in place of mooch. Wordnik defines moocher as "A person having a tendency to repeatedly ask help of others, especially if they are making little effort to help themselves."