Christian Tenhofer, 47, confessed at a trial that he shot the frog from a pneumatic gun because its annoying croaking kept him awake at night, the Focus magazine said Thursday.
Tenhofer also wounded another pet frog by shooting its leg off.
The owner, who kept the dead frog in a refrigerator for several months as evidence to be presented at the court, claimed his pet "never croaked, probably because of some sort of genetic disorder".
The court in the town of Krefeld has decided to fine Tenhofer only after investigators found out that he acquired the gun illegally.
The court ruled that illegal possession of weapons was an aggravating circumstance, Focus said.
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