I'd go with a Lizard tail if it's regenerative properties carried over elsewhere.
If not. Scorpion tail. Who's fucking with scorpion tail guy? Nobody. That's who, at least nobody that doesn't want a poison stinger to the face anyway.
Or maybe a kangroo tail if I don't get immunity to my own poison. They're strong.
Or crocodile, yeah probably that assuming no regen and poison resistance. Since i can't swim well otherwise.
That is assuming everything is designed around tails now.
Otherwise, a bunny tail would be good, for it's non intrusive nature.








