Inspired by this comment which states that beholders can't use eye rays in heavily obscured areas I started thinking that things like fog cloud would be cleared by their anti-magic eye which would limit the benefit.
So, is there any way that a similar effect to fog cloud can be created that will not be suppressed in an anti-magic field?
I am not looking for creative DM fiat answers (Like creating water on top of a bonfire cantrip) just things that are specifically covered within the rules (Such as a non-magical potion of fog if such a thing were to exist).
Note: Other things that obscure vision such as darkness are not what this question is about. Fog cloud is physically obscuring vision so darkvision etc would not be of benefit. The solutions need to come up with similar physical impediments.