Source: totalcomicmayhem.blogspot.com

1. Galactus

I mean, duh.

Like, Batman is a badass through and through, but no matter how much time he has to prepare, he's not of the galactic tier. Galactus is an almighty being who could annihilate the Dark Knight with a single blast of the Power Cosmic. He would be painted across the cosmos like a smear of butter on your breakfast toast.

Bats’ only hope is that Galactus will make him a new herald and give him some cosmic power. In that case, Batman wins. But that's very unlikely. It's far more likely that the big G will simply step on Batman by accident without even realizing that it’s happened.

And there you have it: Five Marvel Characters who could defeat The Batman. But again, these are all fictional characters, so storytelling could necessitate any outcome for any fight. Regardless, these thought experiments are fun.