I am trying to recall the name of a story I read when I was fairly young (maybe 20 years ago, but not sure how old the story is). 

What I remember: A man acquires a set of creatures that he keeps in his house, I think in an aquarium. They evolve over time, quickly, and think of him as their benevolent god. They build statues in his likeness. 

Then, I believe some sort of accident happens, and the statues they build become a little less benevolent, which bothers him. This pattern continues on with his cruelty increasing and their depiction of him becoming more cruel.