Douglas Harper's Etymology Dictionary
"German girlfriend," from German Schatzi, diminutive of Schatz, a term of endearment for a woman, literally "treasure," from Proto-Germanic *skatta- (cognates: Dutch schat "treasure," Gothic skatts "piece of money, money"), originally "cattle."
Wikipedia
Schatzi is an American band from Oklahoma, based in Austin, Texas, formed in 1996 by Montez Williams, Christian Kyle, Jason Westbrook and Jason Altman.
Usage examples of "schatzi".
In some respects Gladys reminded Eddie of Schatzi, the German shepherd bitch he used to have as a boy.
When he used to put his arm around his mother, or kissed her goodbye when he was leaving the house, Schatzi would bark and snarl.
Until he broke her of the habit by beating her with a rolled newspaper, Schatzi would snap at his mother's legs.
Eddie hadn't cried since he was twelve years old, and that was when Schatzi was run over.