You will get a Moxie Honchkrow if Murkrow has its Hidden Ability, which is Prankster. In order to get a Prankster Murkrow you will need to find it in a horde battle in XY (it cannot be obtained with its HA in ORAS). Do this by using Entrainment on the hordes until you find a Murkrow with Prankster. When you evolve this Murkrow into Honchkrow, it will have Moxie.