Kargarok

Making their first appearance in The Wind Waker, Kargaroks (カーゴロック, Kaagorokku) are bird-like creatures that Link faces frequently in his quest.

The Wind Waker
Kargarocs (as their name was spelled in The Wind Waker, see Nintendo Gallery) were used by Ganon for surveillance and transportation of other monsters, such as Moblins, across the sea. The Kargarocs were easily defeated when roosting, and were also susceptible to arrows (and cannon fire) when airborne. Link could glean rare Golden Feathers from the tails of defeated Kargarocs, which fetched a nice price when presented to a certain guard on Dragon Roost Island. An interesting fact is that these creatures bear a resemblance to the Helmaroc King, the giant bird that kidnapped Link's sister, Aryll.

The name "Kargaroc" is most probably derived from "Roc" (as in Roc's Feather), an item featured in various games in the Zelda series.

Twilight Princess
In Twilight Princess, Kargaroks have two distinct incarnations. The first is a common enemy in Hyrule Field, which attempts to knock Link off of Epona. Karagaroks can be easily dispatched with the sword, although this can be difficult on horseback. An alternative method is simply to fire arrows at it, Bomb Arrows being especially effective.

Shadow Kargarok
A Shadow Kargarok is a Kargarok that has been transformed by the effects of the Twilight Realm. It attacks in the same way as a normal Kargarok although its appearance has changed: its body is now black, and its head has been replaced with a horn emblazoned with the Twilight Emblem. Its cries are now a highly computerized trumpeting sound. The Shadow Kargarok found when first entering Lake Hylia is a little harder to defeat. Fyer will spot a bublin from a distance, which must be approached. When it sees Link, it will use the nearby Hawk Grass to call a Shadow Kargarok and then hop on its back. Keep a distance from it, let it have some run way to charge forward, and when it comes close roll and quickly bite it. Also the bublin will shoot fire arrows. Once defeated, Midna takes control of it, and the adventure continues.

Trivia
The computerized horn sound the shadow Kargoroc makes is similar to Articuno's cry in the Pokemon game series.