If someone were to write a biography about us, the following could be reported: #1 - Every basketball player needs a good one. #2 - we can be seen on most Christmas trees. #3 - One of us is a famous Captain. #4 - We are often delivered in square rings. #5 - We often accompany a line and a sinker. Based on the biographical information above --- Who/what are we?
We are Hooks/hook.