I didn't have a pledge name, but my 5th generation lil sis calls me "great stuff." It's a lot easier than calling me her great great great great great grand big.
My lil sis' nickname was "bud." I'm not sure why. I can guess. She didn't drink until she turned after she turned 21 and was very much against it. So we named her after a beer... or at least that is what I think. I guess it can be interpreted in other ways too.