BioBubble Wonder Bubble Tunnel Fish Tank
A tunnel for your betta fish, a feat of physics for your aesthetic pleasure. BioBubble's Wonder Bubble Tunnel Kit is a freshwater fish tank whose egg shape gets super nifty on the top half with an arcing aquatic tunnel that uses positive water pressure to stay filled when its ends are submerged. When your fishies need some exercise or a change of scenery, they can swim on up and through it, perhaps pausing for a bit in the center viewing window to get a better look at what's streaming on Netflix.
Also upping the visuals on the Wonder Bubble Tunnel is an external planting tray you can use to add flowers or plants to your clever ecosystem. Or the Bubble has a flat back for adhering a photo or mirror if you prefer.