Carrybee

Carrybee is an invulnerable airship that dispenses enemies in the desert of Mega Man Zero. It appears in Fefnir's stage in which Zero has to protect the Resistance Base from a large attack. After defeating a number of troops, it'll appear dispensing Pantheons, Kerberos, and Shellcrawlers. After defeating or evading the reinforcements, Fefnir jumps out and challenges you. 

Carrybee G
Carrybee G is a modified Carrybee that dispenses Pantheons in Mega Man Zero 3. It's no longer invulnerable. It appears in the desert stage of Anubis Necromancess V.