Facial hair that all Unix experts are mysteriously compelled to grow. The length, bushiness, and unkemptness of the Unix beard are all directly proportional to the owner's expertise. Having a Unix beard is a great way to ensure that you never get laid.
Bob's a true Unix genius, just look at the size of his Unix beard!
A species of Macaw known for its tendency to alight on one's erect penis. It is not clearly understood why these birds choose to land on penises.
Should a penisbird perch on your pecker, do not panic. The bird will most likely groom himself for a while and leave. Do not harm the penisbird, as they are an endangered species and must be protected.
There is naught more beautiful than a flock of penisbirds in flight, so long as you have your pants up.