LORELAI: God, where is this [inn] again?
RACHEL: Uh, it’s kind of behind the mill. You go over the little footbridge with the mean duck family living under it.
LORELAI: Yes, the Armbrusters.
Lorelai seems to have made a name up for the “mean duck family” under the bridge. Armbruster is a German surname meaning “crossbow”, but in English it sounds a little like “arm bruiser”, which might be what Lorelai is thinking of.
The Annotated Gilmore Girls 