Stocking advice for 20gal AIO

[Dae]

Hello,
I am looking for stocking advice for a tank that I have collecting dust. Its a JBJ 20gallon AIO and I really would like a centerpiece resident. I am looking to house only one fish in this tank but somethin unique. I would like to house a predator but I don't think anything would be comfortable in that small of a tank. (Not planning corals or any inverts)
Let me know what you think!!

 

[2020 Worst Year]

Angler

 

[Thereefgallery]

Yeah there are some small species of anglers that don't require much space.