Birds are some of the enemies that are encountered throughout the Crash Bandicoot series. Their appearance is similar to that of vultures, especially in the second Crash game.
In the original game, they appear in three levels: Slippery Climb, Stormy Ascent (cut level) and The Great Hall. One is seen as Crash and Tawna's transport out of Cortex Castle. They usually fly in high-to-low pattern, but also fly from side to side as seen in the cut level Stormy Ascent.
In Crash Bandicoot 2: Cortex Strikes Back, they appear in the levels Turtle Woods (in the secret area in which there are two of these birds) and The Pits where, upon seeing Crash, they fly at him along the floor. They can be jumped on or over in order to get past. This design reappeared in Crash Bandicoot: The Wrath of Cortex; only in the level Gold Rush. In Crash Bandicoot: The Huge Adventure, the birds are seen in their Crash 2 models and they can be defeated by jumping or spinning them.
There are also ostriches in Turtle Woods. Provided Crash acts quickly, they are more of a help than a hindrance. If Crash jumps onto them quickly from the top while they're putting their head in the ground, Crash can access the higher boxes needed to get the clear gem. Due to their massive size, they can't be defeated, but the ostriches are harmless anyway. Crash must act quickly, however, or he will not be able to reach the higher boxes.