From the Super Mario Wiki
Choppas are aerial aliens living on Planet Blobule, in the game Super Paper Mario. They look like blue-green dragonflies, with two pairs of orange wings. Their name is based on the word "chopper," an alternative name for a helicopter.
Just like Mario, Choppas have the ability to flip between dimensions at will. In fact, they, their relatives, Amazy Dayzees and Dark Dayzees are the only enemies in Super Paper Mario who are able to flip between dimensions even though they are not encircled by a dotted line. Although they are not very aggressive, their movements and attack pattern are quite unpredictable, and defeating them is not always easy. Using Fleep's ability is one of the best ways to get rid of them.
In Super Mario Galaxy 2, an enemy named Choppah had the same name but attacked differently, had an h on the end of the word, and was not aggressive toward Mario.
Names in other languages