Dad acquired the nickname "Buck", sometimes "Buck With a Truck" because he was driving a pickup truck at the time. It never really caught on with anyone but my (now ex-) SIL though, so while I've used it on occasion when the kids were younger, I don't use it now.
What's really confusing: Dad and his siblings had grandparents they referred to as "Ma" and "Pa", even though they ALSO sometimes referred to their own parents as Ma and Pa (and sometimes "Mother" and "Pop"). Occasionally when Dad's telling a family story, I have to ask if he's referring to HIS parents or his dad's parents.