Mavis is or was a young Roc bird.
The son of immense Agrabah-era Roc bird Mavis, who, not having yet learned to fly, often rode on his mother's back, this sweet-natured, easily-saddened Roc Kid was abducted by Abis Mal and his thugs so that they could use his magical feathers to spread havoc in the city with impunity. Aladdin, Abu, Iago and the Genie succeeded in freeing him; the Genie then brought him back to his mother, who, in thanks, helped the heroes of Agrabah defeat the scoundrels.
Behind the scenes
The Roc Kid appears in the 1994 Aladdin episode Air Feather Friends.