From the Super Mario Wiki
Mechanical Zingers are purple-and-yellow striped robotic Zingers and an enemy in Donkey Kong 64. Instead of wings, Mechanical Zingers have a propeller on their head, which they use to stay airborne, and a pair of small wheels for feet. They also have a bomb compartment on their belly, which they store unripe Oranges in.
Mechanical Zingers only appear in the level Frantic Factory, which they appear entirely throughout. They also make a brief appearance in one of Lanky Kong's Hideout Helm challenges, where his objective is to shoot down three Mechanical Zingers. Like their normal counterpart, Mechanical Zingers try to attack the Kongs by dropping unripened, green Oranges on them. Unlike normal Zingers, they do not attempt to dive-bomb at the active Kong.
Mechanical Zingers are slightly more durable than normal Zingers, requiring two shots from a weapon rather than one (although Chunky Kong's Pineapple Launcher defeats them in one hit). The first shot causes the Mechanical Zinger to fly erratically and start smoking. A Mechanical Zinger can also be defeated from an Orange or a Kong's musical instrument, both of which instantly defeat them.