Yiddish: Don't stick your head in a wolf's mouth.

SOURCE: Stutchkoff, Der Oytser fun der Yidisher Shprakh.

שטעק ניט דעם קאָפּ צום וואָלף אין מויל אַרײַן.

Shtek nit dem kop tsum volf in moyl arayn.

Don't stick your head in a wolf's mouth.