It's evaluation time! :D
Intimidate: This is a good ability if you have a Bulk Up Krookodile. Lowering by one stage may not seem like much, but its enough to survive an attack. Use that time to use Bulk Up. Also give it a Sitrus berry. It will make it's hp go up by a fair amount when damaged. If you use Bulk Up before the opponent attacks, they will have -1 attack and you will have +1 defense (and +1 attack!). If they are a powerful opponent, they will put Krookodile at 1%-50% hp. Then the Sitrus Berry kicks in. Then use Bulk Up the next turn for an attack and defence boost, and sweep with the +2 attack.
Moxie: +1 Attack for each opponent knocked out? Good deal! Give it good speed and a ground gem, and make sure that Earthquake is somewhere in the moveset, and OHKO the first enemy. Attack goes up and your opponent's goin' down. A scarfed Krookodile with a good moveset is great. It is easy to start a sweep if you send it in at just the right time.
In the end, I choose…Moxie! In my opinion, Moxie is one of the best Pokemon abilities. Plus, Krookodile is more offensive than defensive.
I hope this helps! -Jellohamster