The word "schnickelfritz" is a term of endearment of uncertain Germanic origin. It means something akin to '
rascal', 'scamp', or 'little chatterbox'. The word is usually used with children, but can also be used between others who are close with each other.
Also, Schnickel Fritz is a folklore
character. Fritz was a rascally little boy. He also is mentioned in the Schnitzelbank
song. (Google the song...I'm not chronicling it here.)