I added a texture to the bowl, and it came out rendered black. I unwrapped it, and I did a little node editing, to make the plane glossy and B&W. It looks fine in the preview, as well as in material view, and in rendered view, but not in the render.
Another weird part is that Suzanne is also black in the render, even though she just has the default light gray material and no node editing at all. If I render without the bowl, it's just Suzanne in black. I have no idea why this is happening.
Here's my bowl's nodes:
And here's rendered view
And here's the render
There's definitely a light in the scene.