Oh boy...
I don't know how many gallons this would be but I know it's totally impossible so who cares.
1/3 every central/south American cichlid/rays/cats.
1/3 1,000,000,000,000,000 neon tetras.
1/3 shark tank. Big nasty bull sharks (of coarse I want a white shark but we all know they can't be kept in captivity

haha)
And lastly 1/3 (yes...4 1/3's. Because I thought of this late and I don't want 1/4's) bottle nose dolphin tank.
Oh oh oh... And nothing special cause this WILL happen when I decide to finally go salt. A tank with a dogface puffer,snowflake eel, and a pistol shrimp.