sommelier knife
waiter's friend

Also called sommelier knife, a popular type of corkscrew used in the hospitality industry.

Some sommelier knives have two steps on the lever, and often also a bottle opener.

A sommelier knife, waiter's friend or wine key is a corkscrew in a folding body similar to a pocket knife.

The titular character's transformation requires a bottle of wine to be inserted into a transformation belt that acts as a wine opener, and he is armed with a sword that resembles a corkscrew as well as a sommelier knife.