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✅ Answers
First of all it depends where you live… different countries and/or states have different laws as to what’s legal.
As for aquatic mammals (I’m guessing you mean something like an otter?), I’m not aware of any country/state where it is legal to own one as a pet.
You could get a sea horse or a small shark. I don’t know what they are called but they are really small, like the length of your arm.
Perry!………..The Platypus
Source(s): Phineas and Ferb
uhh you can get a sting ray,eel,shark,and (not aquatic)……… HEDGEHOG
Source(s): LUV HEDGEHOGS