A friend(pal) who's burden(albatross) outweighs the benefits of their friendship.
A palbatross is someone who comes over and drinks your beer (but never brings any), keeps you up all nighttalking about their problems (but never listens to yours), or can never return a ride to the airport (despite you giving them dozens.) You wonder why they are even your friend?
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!