Abis Mal is or was a human man.
Abis Mal was a thief living in the ancient city of Agrabah. Abis claimed to be a cunning swashbuckling bandit and master swordsman, but these were mostly narcissistic delusions; he was, at one point, the leader of a gang, but was brutally kicked out of it after Abis failed to protect their loot from local do-gooder Aladdin.
From then on, after a disastrous attempt to associate with evil genie Jafar, Abis stuck with the calm and collected Haroud, and, thanks to his advice, managed to repeatedly antagonize Aladdin (now his archenemy of a sort) in the following years.
It is unknown if Abis Mal and Haroud included in whatever weird phenomenon transplanted Agrabah from ancient to modern times later on.