Sulcatas tortoise. Lmao, you could ride those things around. Little big for a fish tank, methinks.
I like russian tortoises. That would be my choice seeing as how they generally require less maintenance than aquatic turtles and they're just so darn cute. Plus, they only get around 5 inches.
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Current setups: 1800 gallon koi pond, 10 gallon planted, 150 gallon reef, other FOWLR tanks