I really like this. I did something similar but on a cart so I could roll it into the garage for overwintering. It wasn't this pretty though, to be honest.
I'm not sure what species your frog is, but if it's an aquatic species that will grow larger (leopard frog, bullfrog, that sort of thing), you might want to fish it out and find it a good home. If large frogs continue to live in the barrel, they will devour your livestock entirely. They're super predators; I recall a young 3" bullfrog eating 2" goldfish. At that size it will happily eat your shrimp and smaller fish.