This is a German Third Reich dress bayonet, identified by its maker's mark for Carl Eickhorn. 

The blade is nickel-plated, which was typical for dress or parade bayonets. 

The maker's mark is a squirrel holding a sword, which is the logo for Carl Eickhorn of Solingen, a prominent manufacturer of German edged weapons. 

It features black, molded plastic (bakelite) grips with a checkered pattern. 

These were ceremonial items used for parades and other official events, not typically for combat