Pokémon with Special Ability in the wilds?

I started a new run with a couple of friends, and I wanted to use a Woobat in my team, because, you know, Simple is just a good Ability. But, one thing I’m not understanding is, can I get one in the grass/cave/ecc. with that ability? or do I have to use a Dream Mist to obtain Simple as the ability of Woobat?