How to make a Flying Mob

I searched around but couldn't find an answer (ofc most forums were outdated)) so i figure i give it a try

Has anybody found away to make a entity (mob) fly?

I played around with the procedures that involved in flying to see if i can make my entity (mob) fly but it never would  

i even used the new potion effect to make a flying potion but that didn't work either

Has anybody found a way?