Crowber

Crowbers, also simply known as Crows, are raven-like enemies first seen in New Super Mario Bros. These enemies tend to appear in the last courses of the game, where they attack Mario or any other potential victim with rather fast moves. The name Crowber appears to be a pun from "crowbar," a tool used to remove nails.

New Super Mario Bros.
Crowbers are only seen in World 8-1, where they swoop down to attack Mario. As progress is made throughout the course, more will appear and chase after the player. Crowbers attack quickly, making it somewhat difficult for the player to defeat them.

New Super Mario Bros. Wii
Crowbers reappear in the game New Super Mario Bros. Wii. They are redesigned with a purple plumage and a lighter beak and legs, and appear in and World 8-5. They attack in the same manner as they did in New Super Mario Bros.

New Super Mario Bros. 2
Crowbers reappear in New Super Mario Bros. 2. They appear in, World 6-4 and in the first level of the Impossible Pack. They maintain their appearance from New Super Mario Bros. Wii.

New Super Mario Bros. U
Crowbers were originally going to appear in New Super Mario Bros. U, but were not used in the final product. They can be seen, however, in one of many unused stages. As seen in it, they were intended to act and attack like they did in previous New Super Mario Bros. installments.

Dr. Mario World
Crowbers make their debut in the Dr. Mario series in Dr. Mario World as obtainable assistants. In this game, they revert back to their black coloration.

Paper Mario: The Origami King
After being cut from Paper Mario: Sticker Star, Crowbers make their Paper Mario series debut in Paper Mario: The Origami King, where origami Crowbers are seen flying around a desert area and an island with a large skull.

Trivia

 * Crowbers were going to reappear in Paper Mario: Sticker Star, but were cut from the game. However, a Toad Quiz in Mario & Luigi: Paper Jam has the enemy's name as one of the answers.